Week 04 · Divide by two-digit numbers
Tuesday
Divide in chunks
// Estimate, divide in chunks and check
⏱ about 15 min
Tuesday: Divide in chunks
Samantha the Squirrel finds 768 pinecone seeds under the tall pines.
"Fun fact: a group of 24 seeds fills one of my tiny pouches," she says.
"How many pouches can I fill?"
Bennie the Bear picks up a stick and writes in the dirt.
"We do not need to find the answer in one jump," he says.
"We can take away big friendly chunks of 24, like 20 pouches at a time."
Samantha flicks her tail. "Chunks! I love chunks."
Learn it: partial quotients
Divide 768 ÷ 24.
30 groups of 24 is 720. Take it away: 768 - 720 = 48.
2 groups of 24 is 48. Take it away: 48 - 48 = 0.
Add the chunks: 30 + 2 = 32.
So 768 ÷ 24 = 32.
Check: a rectangle 32 by 24 has an area of 32 × 24 = 768.
DIVIDE 768 ÷ 24
- Think about how Bennie divides.
- Tap the steps in order.
1First
2Next
3Then
4Last
FRIENDLY CHUNKS
- Read the question.
- Tap your answer.
24 × 20 = ?
35 × 10 = ?
18 × 30 = ?
42 × 5 = ?
WHAT IS LEFT?
- Read the question.
- Tap your answer.
768 - 480 = ?
630 - 350 = ?
864 - 720 = ?
DIVIDE IN CHUNKS
- Read the question.
- Tap your answer.
768 ÷ 24 = ?
630 ÷ 35 = ?
864 ÷ 18 = ?
1,134 ÷ 42 = ?
Multiply the quotient by the divisor to check.
| Sentence | True or false? |
|---|---|
| 768 ÷ 24 = 32 | ? |
| 630 ÷ 35 = 20 | ? |
| 864 ÷ 18 = 48 | ? |
| 20 + 12 = 768 ÷ 24 | ? |
WHY THIS EXERCISE35 × 20 is 700, so 630 ÷ 35 is less than 20. It is 18.
Try it
Count out 96 small things, like beans or buttons.
Make piles of 12. First make 5 piles at once, which is 60.
Keep making piles of 12 until none are left.
Add up all your piles. What is 96 ÷ 12?
Make piles of 12. First make 5 piles at once, which is 60.
Keep making piles of 12 until none are left.
Add up all your piles. What is 96 ÷ 12?
Show 864 ÷ 18 with chunks. Write each chunk you take away.
Chunky and clever! Tomorrow we divide four-digit numbers.