🔢 Math · Grade 3
One printable 40-minute plan for each of the 22 lessons. A substitute can run any lesson with the lesson's 3D video and Movie. No account needed.
Lesson 1: Multiplication is equal groups
Lesson link: books/g3-math · lesson 1
Big idea: 4 × 5 means 4 groups of 5.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“4 bags with 5 apples each: you could count by ones, or multiply.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Four bags, five apples in each.
- Skip count by fives: 5, 10, 15, 20.
- Line them up: 4 rows of 5. Four times five equals twenty.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
3 rows of 6 chairs. How many chairs?
Answer (for the teacher): 18
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
6 × 0 = ?
Answer (for the teacher): 0
Leave on the board
- Multiplication is equal groups
- Big idea: 4 × 5 means 4 groups of 5.
- Memory trick: “Groups times how many in each.”
- Goal: 100%
Watch for this mistake
- Adding 4 + 5 instead of multiplying.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 2: Division is fair sharing
Lesson link: books/g3-math · lesson 2
Big idea: Division splits into equal groups.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“12 cookies shared by 3 friends: each gets the same amount.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Twelve cookies, three friends. Share one at a time.
- Each friend gets four.
- Multiplication checks division: 3 times 4 is 12.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
20 stickers shared by 4 kids. Each gets?
Answer (for the teacher): 5
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
24 ÷ 4 = ?
Answer (for the teacher): 6
Leave on the board
- Division is fair sharing
- Big idea: Division splits into equal groups.
- Memory trick: “Divide = share fairly.”
- Goal: 100%
Watch for this mistake
- Forgetting division and multiplication are related.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 3: Arrays and word problems
Lesson link: books/g3-math · lesson 3
Big idea: Rows times columns gives the total in an array.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“A garden has 4 rows with 6 tomato plants in each row.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Four rows with six plants in each row.
- Multiply rows by columns: 24 plants.
- Know the total and the rows? Divide: 24 divided by 4 is 6 in each row.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
5 rows of 7 seats. How many seats?
Answer (for the teacher): 35
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
42 cards in 6 equal piles. Cards in each pile?
Answer (for the teacher): 7
Leave on the board
- Arrays and word problems
- Big idea: Rows times columns gives the total in an array.
- Memory trick: “Rows times columns.”
- Goal: 100%
Watch for this mistake
- Adding the rows and columns (4 + 6) instead of multiplying.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 4: Find the unknown number
Lesson link: books/g3-math · lesson 4
Big idea: Use a fact you know to find the missing number.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“8 × ? = 48. A missing number is a mystery you can solve.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Eight times what number is forty-eight?
- Think: 8 times 6 is 48, so the mystery number is 6.
- For division, multiply back: 3 times 5 is 15, so 15 divided by 3 is 5.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
? × 7 = 56
Answer (for the teacher): 8
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
6 × ? = 42
Answer (for the teacher): 7
Leave on the board
- Find the unknown number
- Big idea: Use a fact you know to find the missing number.
- Memory trick: “Cover it, then ask: what fact do I know?”
- Goal: 100%
Watch for this mistake
- Writing the total (48) as the missing number.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 5: Properties and fact strategies
Lesson link: books/g3-math · lesson 5
Big idea: Turn it around, break it apart.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“If you know 3 × 8, you know 8 × 3. Strategies make all facts to 10 × 10 quick.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model. This lesson has 2 3D videos in a row: press Next and ▶ Play for each part.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Commutative: 3 times 8 equals 8 times 3. Order doesn't change the product.
- Associative: group the factors any way you like. 2 times 5 times 3 is 30 either way.
- Break it apart: 7 times 6 is 35 plus 7: 42.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
6 × 7 = ?
Answer (for the teacher): 42
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
56 ÷ 8 = ?
Answer (for the teacher): 7
Leave on the board
- Properties and fact strategies
- Big idea: Turn it around, break it apart.
- Memory trick: “Know one, get two.”
- Goal: 100%
Watch for this mistake
- Not using known facts to build new ones.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 6: Two-step word problems
Lesson link: books/g3-math · lesson 6
Big idea: Step 1, then step 2, then check.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“Some problems need two steps. Find the first answer, then use it.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Three packs of 4 pencils, then give away 5.
- First multiply, then subtract: 7 left. A letter like n stands for the unknown.
- Estimate to check: 10 minus 5 is 5. 7 is close, so it makes sense.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
Maria has 2 boxes of 8 crayons and buys 6 more. How many?
Answer (for the teacher): 22
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
Which equation fits: 3 packs of 4, give away 5, n left?
- A. 3 × 4 − 5 = n
- B. 3 + 4 − 5 = n
Answer (for the teacher): 3 × 4 − 5 = n
Leave on the board
- Two-step word problems
- Big idea: Step 1, then step 2, then check.
- Memory trick: “Two questions in one.”
- Goal: 100%
Watch for this mistake
- Stopping after the first step.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 7: Patterns in math
Lesson link: books/g3-math · lesson 7
Big idea: Patterns follow a rule; find the rule and explain it.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“A times table hides patterns that help you check your answers.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Multiples of 4: add 4 each time.
- Four times any number is always even.
- Odd plus odd: the two leftovers make a pair, so the sum is even. 3 plus 5 is 8.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
What comes next: 6, 12, 18, 24, ?
Answer (for the teacher): 30
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
Next: 50, 45, 40, 35, ?
Answer (for the teacher): 30
Leave on the board
- Patterns in math
- Big idea: Patterns follow a rule; find the rule and explain it.
- Memory trick: “Find the rule, test the rule.”
- Goal: 100%
Watch for this mistake
- Guessing the next number without checking the rule on every step.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 8: Round to the nearest 10 or 100
Lesson link: books/g3-math · lesson 8
Big idea: Look at the digit to the right; 5 or more rounds up.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“About how many students are at school? Rounding gives a quick, friendly number.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Nearest ten: 467 is between 460 and 470, closer to 470.
- Nearest hundred: 467 is between 400 and 500, closer to 500.
- Exactly halfway? We round up: 350 becomes 400.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
Round 238 to the nearest ten:
Answer (for the teacher): 240
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
Round 994 to the nearest ten:
Answer (for the teacher): 990
Leave on the board
- Round to the nearest 10 or 100
- Big idea: Look at the digit to the right; 5 or more rounds up.
- Memory trick: “5 or more, raise the score; 4 or less, let it rest.”
- Goal: 100%
Watch for this mistake
- Looking at the wrong digit.
- Changing digits to the left that should stay the same.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 9: Add and subtract within 1,000
Lesson link: books/g3-math · lesson 9
Big idea: Line up places; regroup when needed.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“A school library has 356 books and gets 278 more.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model. This lesson has 2 3D videos in a row: press Next and ▶ Play for each part.
- Press Next to the Movie step and press ▶ Play.
The video says:
- 356 books plus 278 more. Line up hundreds, tens and ones.
- Ones make 14: write 4, regroup 1 ten.
- Then the tens, then the hundreds: 634 books.
- Check by subtracting: 634 minus 278 gives back 356.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
503 − 248 = ?
Answer (for the teacher): 255
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
812 − 356 = ?
Answer (for the teacher): 456
Leave on the board
- Add and subtract within 1,000
- Big idea: Line up places; regroup when needed.
- Memory trick: “Same places together.”
- Goal: 100%
Watch for this mistake
- Forgetting to regroup.
- Taking the smaller digit from the bigger one in every column.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 10: Multiply by multiples of 10
Lesson link: books/g3-math · lesson 10
Big idea: Multiply the basic fact, then think in tens.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“4 boxes of 30 crayons: use 4 × 3, then think in tens.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Four groups of thirty crayons.
- Four times three tens is twelve tens.
- Twelve tens is 120 crayons.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
6 × 40 = ?
Answer (for the teacher): 240
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
3 × 90 = ?
Answer (for the teacher): 270
Leave on the board
- Multiply by multiples of 10
- Big idea: Multiply the basic fact, then think in tens.
- Memory trick: “Fact first, then tens.”
- Goal: 100%
Watch for this mistake
- Writing 5 × 60 = 30: forgetting the tens.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 11: Unit fractions and equal parts
Lesson link: books/g3-math · lesson 11
Big idea: Bottom = equal parts; top = parts you have.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“Cut a pizza into 4 equal slices; one slice is ¼.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Cut a pizza into 4 equal slices. One slice is one fourth.
- Three fourths: three of four equal parts.
- A shape cut into 6 equal parts: each part is one sixth.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
A bar has 6 equal parts; 5 are shaded. Fraction shaded?
Answer (for the teacher): 5/6
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
Equal parts must be…
- A. The same size
- B. Any size
Answer (for the teacher): The same size
Leave on the board
- Unit fractions and equal parts
- Big idea: Bottom = equal parts; top = parts you have.
- Memory trick: “Denominator: Down, how many parts.”
- Goal: 100%
Watch for this mistake
- Counting parts that are not equal.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 12: Fractions on a number line
Lesson link: books/g3-math · lesson 12
Big idea: Cut 0 to 1 into equal jumps; count the jumps.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“A 1-mile walk with a water stop every quarter mile.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Four equal jumps from 0 to 1: each jump is one fourth.
- Three jumps land on three fourths.
- Four fourths lands on 1.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
0 to 1 is cut into 3 equal jumps. Where do 2 jumps land? (fraction)
Answer (for the teacher): 2/3
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
6/6 is the same point as…
Answer (for the teacher): 1
Leave on the board
- Fractions on a number line
- Big idea: Cut 0 to 1 into equal jumps; count the jumps.
- Memory trick: “Count the spaces, not the marks.”
- Goal: 100%
Watch for this mistake
- Counting tick marks (including 0) instead of spaces.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 13: Equivalent fractions and wholes
Lesson link: books/g3-math · lesson 13
Big idea: Same whole, same amount.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“½ a sandwich or 2/4 of the same sandwich: same lunch.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model. This lesson has 2 3D videos in a row: press Next and ▶ Play for each part.
- Press Next to the Movie step and press ▶ Play.
The video says:
- One half, two fourths, four eighths: the same amount.
- Equivalent fractions sit at the same point on the number line.
- Three wholes is 3/1. Four fourths is 1 whole.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
½ = ?/6
Answer (for the teacher): 3
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
2/3 = ?/6
Answer (for the teacher): 4
Leave on the board
- Equivalent fractions and wholes
- Big idea: Same whole, same amount.
- Memory trick: “Same size, different name.”
- Goal: 100%
Watch for this mistake
- Comparing fractions with different wholes.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 14: Compare fractions
Lesson link: books/g3-math · lesson 14
Big idea: Same bottom: compare tops. Same top: fewer parts is bigger.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“Would you rather have ⅓ or ⅙ of the same pizza?”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Same denominator: 5 pieces beat 3 pieces. 5/8 is greater.
- Same numerator: thirds are bigger pieces than sixths. 2/3 is greater than 2/6.
- Only compare fractions of the same-size whole.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
Compare 2/3 and 2/6. Which is bigger?
- A. 2/3
- B. 2/6
Answer (for the teacher): 2/3
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
4/6 vs 5/6: smaller?
- A. 4/6
- B. 5/6
Answer (for the teacher): 4/6
Leave on the board
- Compare fractions
- Big idea: Same bottom: compare tops. Same top: fewer parts is bigger.
- Memory trick: “More parts, smaller pieces.”
- Goal: 100%
Watch for this mistake
- Thinking ¼ > ½ because 4 > 2.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 15: Time to the minute
Lesson link: books/g3-math · lesson 15
Big idea: Count on from start to end to find elapsed time.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“Recess starts at 10:15 and ends at 10:40. How long is recess?”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Recess starts at 10:15 and ends at 10:40.
- Jump 5 minutes to 10:20, then 20 minutes to 10:40.
- Five plus twenty: recess is 25 minutes.
- Read a clock: count by fives, then by ones. 7:43.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
From 3:20 to 3:55 is how many minutes?
Answer (for the teacher): 35
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
Practice ends at 6:50. It was 40 minutes long. It started at…
- A. 6:10
- B. 6:30
Answer (for the teacher): 6:10
Leave on the board
- Time to the minute
- Big idea: Count on from start to end to find elapsed time.
- Memory trick: “Jump to friendly times.”
- Goal: 100%
Watch for this mistake
- Treating 60 minutes like 100.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 16: Mass and liquid volume
Lesson link: books/g3-math · lesson 16
Big idea: Grams and kilograms measure mass; liters measure liquid.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“Is a bag of apples measured in grams or kilograms?”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- A paper clip has a mass of about one gram.
- A big textbook is about one kilogram: 1,000 grams.
- A big water bottle holds about one liter.
- A tank holds 45 liters. Pour out 18 liters: 27 liters are left.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
3 bags of rice, 4 kg each. Total kg?
Answer (for the teacher): 12
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
A bike's mass is best measured in…
- A. Kilograms
- B. Liters
Answer (for the teacher): Kilograms
Leave on the board
- Mass and liquid volume
- Big idea: Grams and kilograms measure mass; liters measure liquid.
- Memory trick: “Tiny things: grams. Heavy things: kilograms.”
- Goal: 100%
Watch for this mistake
- Using liters for mass, or grams for liquid.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 17: Scaled picture and bar graphs
Lesson link: books/g3-math · lesson 17
Big idea: Check the key or scale first.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“A class vote: the key says each 🙂 = 2 votes.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- In a picture graph, one symbol can stand for 2 votes.
- In a bar graph, read where the bar ends on the scale.
- Subtract to answer how many more: 12 minus 7 is 5.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
Key: 🙂 = 2. Pizza has 4 🙂. Votes?
Answer (for the teacher): 8
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
Always read the…
- A. Key or scale
- B. Color
Answer (for the teacher): Key or scale
Leave on the board
- Scaled picture and bar graphs
- Big idea: Check the key or scale first.
- Memory trick: “Key first, then count.”
- Goal: 100%
Watch for this mistake
- Counting symbols as 1 when the key says 2.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 18: Line plots with halves and fourths of an inch
Lesson link: books/g3-math · lesson 18
Big idea: Measure to the nearest ½ or ¼ inch; mark an X.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“Measure 10 pencils to the nearest quarter inch, then show the data.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- A ruler splits each inch into halves and fourths.
- This pencil ends at three and one fourth inches.
- Put one X above each measurement on the line plot.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
A line plot has 4 X's over 3½ inches. How many items measured 3½ inches?
Answer (for the teacher): 4
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
A line plot's scale is…
- A. A number line marked in units
- B. A key with pictures
Answer (for the teacher): A number line marked in units
Leave on the board
- Line plots with halves and fourths of an inch
- Big idea: Measure to the nearest ½ or ¼ inch; mark an X.
- Memory trick: “One X for each thing measured.”
- Goal: 100%
Watch for this mistake
- Counting the tick marks on the ruler as inches.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 19: Area: count square units
Lesson link: books/g3-math · lesson 19
Big idea: Area is how many unit squares cover a shape.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“How many square tiles cover the floor of a play tent?”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- A unit square is 1 unit long on each side.
- Tile with no gaps and no overlaps.
- Count them: 12 square units.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
A shape is covered by 15 unit squares, no gaps. Area in square units?
Answer (for the teacher): 15
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
Tiles must have…
- A. No gaps or overlaps
- B. Spaces between them
Answer (for the teacher): No gaps or overlaps
Leave on the board
- Area: count square units
- Big idea: Area is how many unit squares cover a shape.
- Memory trick: “Cover it, count it.”
- Goal: 100%
Watch for this mistake
- Leaving gaps between tiles.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 20: Area: multiply and break apart
Lesson link: books/g3-math · lesson 20
Big idea: Area = length × width; split odd shapes into rectangles.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“An L-shaped garden: split it into two rectangles.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model. This lesson has 2 3D videos in a row: press Next and ▶ Play for each part.
- Press Next to the Movie step and press ▶ Play.
The video says:
- A 6 by 4 rectangle: 4 rows of 6 is 24 square units.
- Split a side: 7 times 8 is 7 times 5 plus 7 times 3: 35 plus 21 is 56.
- An L-shape: split it into rectangles and add the areas: 12 plus 10 is 22.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
Rectangle 7 by 3. Area?
Answer (for the teacher): 21
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
Rectangle area 32, one side 4. Other side?
Answer (for the teacher): 8
Leave on the board
- Area: multiply and break apart
- Big idea: Area = length × width; split odd shapes into rectangles.
- Memory trick: “Split it, multiply, add.”
- Goal: 100%
Watch for this mistake
- Counting a shared section twice when splitting a shape.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 21: Perimeter and the unknown side
Lesson link: books/g3-math · lesson 21
Big idea: Perimeter is the distance around: add all the sides.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“Perimeter is the fence around; area is the grass inside.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Perimeter is the fence around. A 6 by 4 rectangle: 6 plus 4 plus 6 plus 4 is 20 units.
- Missing side: 20 minus 6, 4 and 6 leaves 4.
- 5 by 1 and 3 by 3 both have perimeter 12, but areas 5 and 9.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
Rectangle 7 by 3. Perimeter?
Answer (for the teacher): 20
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
Both have perimeter 12. Which has more area?
- A. 3 by 3 square
- B. 5 by 1 rectangle
Answer (for the teacher): 3 by 3 square
Leave on the board
- Perimeter and the unknown side
- Big idea: Perimeter is the distance around: add all the sides.
- Memory trick: “Around = perimeter; inside = area.”
- Goal: 100%
Watch for this mistake
- Mixing up area and perimeter.
Students do not need accounts; progress stays on each device.
Notes for the teacher
Lesson 22: Shapes and quadrilaterals
Lesson link: books/g3-math · lesson 22
Big idea: Shapes share attributes; quadrilaterals all have 4 sides.
Read this aloud (it is the lesson's hook). Students think, then tell a partner what they notice.
“A square, a rhombus and a rectangle are all quadrilaterals: 4-sided shapes.”
- Open the lesson link on the board.
- Press Next to the 🎬 Watch in 3D step and press ▶ Play. Students can drag to turn the model.
- Press Next to the Movie step and press ▶ Play.
The video says:
- Every quadrilateral has four sides and four angles.
- Rectangles have four right angles.
- A rhombus has four sides of equal length.
- A square is a rectangle and a rhombus.
Students open the same lesson on their own device (or work with the board). Press Next to Try it.
Try it together first:
Is a square a rhombus?
- A. Yes
- B. No
Answer (for the teacher): Yes
🧱 Build it: the lesson's short 3D build game. Let students play it after Try it. Its score never changes grades.
If time is left, students play the lesson's game steps (they show up between the videos and Check).
Students press Next to Check and answer the 4 questions on their own device. Goal: 100%. 95% or more is Mastered. “Not yet” means try again; students may retry.
Read this question aloud. Students write the answer on a slip of paper with no name or with a class number, and hand it in.
Is every rectangle a quadrilateral?
- A. Yes
- B. No
Answer (for the teacher): Yes
Leave on the board
- Shapes and quadrilaterals
- Big idea: Shapes share attributes; quadrilaterals all have 4 sides.
- Memory trick: “Quad means four.”
- Goal: 100%
Watch for this mistake
- Thinking a square is not a rectangle.
Students do not need accounts; progress stays on each device.