Lesson 3.2 · Division
Dividing by one-digit numbers
How do you split 156 stickers among 6 friends? No multiplication fact gives you the answer right away. But place value lets you divide a big number one chunk at a time, and that works for dividends all the way up to the thousands.
Dividing with place value
Start with numbers that end in zeros. Think about what you are dividing:
- : 8 hundreds split into 4 groups is 2 hundreds each. So .
- : 120 is 12 tens. 12 tens split into 3 groups is 4 tens. So .
- : 2,400 is 24 hundreds. 24 hundreds split into 6 groups is 4 hundreds. So .
Each one is a basic fact (, , ) with a place value name attached.
Partial quotients
For numbers that don't end in zeros, take away easy groups one chunk at a time. Here is :
| Take away | How many 6s | What's left |
|---|---|---|
| 10 | ||
| 10 | ||
| 6 | ||
| Total | 26 |
You took away sixes, so . Check: . ✓
Big chunks save time. With you could do it in two steps: , then , for a total of .
Dividing place by place
A shorter way is to divide one place at a time, starting with the largest place. The steps repeat: divide, multiply, subtract, bring down.
Dividing place by place
- Divide the digit (or digits) in the largest place you can.
- Multiply that part of the quotient by the divisor.
- Subtract to see what is left in that place.
- Bring down the next digit and repeat.
Whatever is left after the ones place is the remainder.
Worked example: Two digits, no remainder
Find .
- Tens: 8 tens 4 = 2 tens, with nothing left over.
- Ones: 4 ones 4 = 1 one.
So . Check: . ✓
Worked example: Three digits with a remainder
Find .
- Hundreds: 4 hundreds 3 = 1 hundred. , and hundred is left.
- Tens: 1 hundred is 10 tens. Bring down the 3 to get 13 tens. 13 tens 3 = 4 tens. , and ten is left.
- Ones: Bring down the 7 to get 17 ones. . , and is left.
Nothing is left to bring down, so 2 is the remainder. .
Check: . ✓
Worked example: Four digits
Find .
- Thousands: There is only 1 thousand, not enough to give each of 5 groups a thousand. Trade it: 1 thousand and 2 hundreds make 12 hundreds.
- Hundreds: 12 hundreds 5 = 2 hundreds. , and hundreds are left.
- Tens: Bring down the 4 to get 24 tens. 24 tens 5 = 4 tens. , and tens are left.
- Ones: Bring down the 5 to get 45 ones. , with nothing left.
. Check: . ✓
Common mistake
Don't skip a place when it has a zero in the quotient. For : 6 hundreds 3 = 2 hundreds. Then 2 tens 3 = 0 tens (2 tens are left). Then 24 ones 3 = 8. The answer is 208, not 28. Write the 0 so the other digits stay in the right places.
Tip
Estimate first so you can catch big mistakes. is a little less than , so an answer of about 145 makes sense.
Practice
Find .
Type a number.
Find .
Type a number.
Find .
Type a number.
A school has 378 chairs. They are set up in 6 equal rows. How many chairs are in each row?
Type a number.
Find . Write your answer like 12 R 3.
Type your answer
Find .
Type a number.
A factory packs 2,184 batteries into 8 equal boxes. How many batteries go in each box?
Type a number.
Find . Write your answer like 12 R 3.
Type your answer