🧪 Math Lab 🔢 Unit 1 ✕ Unit 2 ÷ Unit 3 📊 Bar Models

÷ Unit 3: Multi-Digit Division

Sharing, grouping, and remainders — divide with confidence!

🤝 3.1 — Division as Sharing

SHARING

Division means splitting a total into equal groups. Each group gets the same amount!

When to use this model: Use sharing division when you know the total and the number of groups, and you want to find how many in each group.
Sharing means splitting into equal groups. 24 items shared among 6 groups = 4 in each group.

✏️ Practice: Sharing

1Share 24 cookies among 6 friends. Each friend gets the same number. How many cookies does each friend get?
🤔 Think: 24 ÷ 6 = ?
Model: Sharing Division. Split 24 equally into 6 groups. 24 ÷ 6 = ?
Answer: 24 ÷ 6 = 4 cookies each
215 pencils are shared equally among 5 students. How many pencils does each student get?
🤔 Divide the total by the number of students.
Model: Sharing Division. 15 ÷ 5 = ?
Answer: 15 ÷ 5 = 3 pencils each
336 marbles are shared equally among 4 friends. How many marbles does each friend get?
🤔 36 divided into 4 equal groups.
Model: Sharing Division. 36 ÷ 4 = ?
Answer: 36 ÷ 4 = 9 marbles each

📦 3.2 — Division as Grouping

GROUPING

Division can also mean finding how many groups of a certain size fit into the total.

When to use this model: Use grouping division when you know the total and the size of each group, and you want to find the number of groups.
How many groups of 6 can you make from 30? 30 ÷ 6 = 5 groups.

✏️ Practice: Grouping

1How many groups of 6 can you make from 30?
🤔 How many times does 6 fit into 30?
Model: Grouping Division. 30 ÷ 6 = ?
Answer: 30 ÷ 6 = 5 groups
2How many groups of 8 can you make from 40?
🤔 40 ÷ 8 = ?
Model: Grouping Division. 40 ÷ 8 = ?
Answer: 40 ÷ 8 = 5 groups
3How many groups of 9 can you make from 27?
🤔 27 divided into groups of 9.
Model: Grouping Division. 27 ÷ 9 = ?
Answer: 27 ÷ 9 = 3 groups

🔄 3.3 — Division with Remainders

REMAINDERS

When numbers don't divide evenly, we get a remainder — the leftover part!

When to use this model: Any time a number can't be split perfectly into equal groups — the remainder tells us how many are left over.
19 ÷ 6 = 3 R1 — 3 full groups of 6, with 1 leftover.

✏️ Practice: Remainders

1Share 22 stickers equally among 5 friends. How many stickers does each friend get? How many are left over?
🤔 22 ÷ 5 — does 5 divide evenly into 22?
Model: Remainder Division. 22 ÷ 5 = 4 R2. 5 × 4 = 20, 22 − 20 = 2 left over.
Answer: 22 ÷ 5 = 4 stickers each, 2 leftover
2You have 31 cookies. You put them into bags of 7. How many full bags can you make? How many cookies are left over?
🤔 31 ÷ 7 = ?
Model: Remainder Division. 31 ÷ 7 = 4 R3.
Answer: 31 ÷ 7 = 4 bags, 3 leftover cookies
347 pencils are packed in boxes of 8. How many full boxes? How many pencils left over?
🤔 47 ÷ 8 — think about your 8× multiplication facts!
Model: Remainder Division. 47 ÷ 8 = 5 R7.
Answer: 47 ÷ 8 = 5 boxes, 7 pencils leftover

⭐ 3.4 — Long Division (1-Digit Divisor)

LONG DIVISION

Master the long division algorithm: Divide → Multiply → Subtract → Bring Down!

When to use this model: Use the division scaffold for any multi-digit division. It breaks the problem into manageable digit-by-digit steps.
380 ÷ 4 = ?
0
3
8
0
Use the ➡️ Next Step button to walk through the division algorithm step by step!

📊 Visual Connection

✏️ Practice: Long Division

1608 ÷ 4 = ? Use long division!
🤔 Divide 6 ÷ 4 first. Then bring down the next digits.
Model: Long Division. 608 ÷ 4 = 152. Divide: 4 goes into 6 once (1), 6 − 4 = 2. Bring down 0 → 20 ÷ 4 = 5. Bring down 8 → 8 ÷ 4 = 2.
Answer: 608 ÷ 4 = 152
2525 ÷ 5 = ?
🤔 5 ÷ 5 = 1, then bring down the next digit!
Model: Long Division. 525 ÷ 5 = 105.
Answer: 525 ÷ 5 = 105
3936 ÷ 3 = ?
🤔 9 ÷ 3 = 3. Then... what about 3 ÷ 3 and 6 ÷ 3?
Model: Long Division. 936 ÷ 3 = 312.
Answer: 936 ÷ 3 = 312

🌍 3.5 — Interpreting Remainders in Word Problems

REAL WORLD

In real life, what do we do with the remainder? Sometimes we round up, sometimes we drop it, sometimes it's the answer itself!

When to use this model: When the division leaves leftovers, read the question carefully — does the answer need an extra group? Do we ignore the leftover? Or is the leftover the answer?

🎯 3.6 — Mixed Review

REVIEW

Put it all together! Solve problems covering sharing, grouping, remainders, and long division.

When to use this model: Read each problem carefully — decide whether to share, group, use long division, or interpret a remainder.