Compatible numbers

1. Estimating Quotients
Using Compatible Numbers

2. Compatible Numbers
To find compatible numbers, look at the first
two numbers in the dividend (the larger
number in your division problem).
528 ÷ 7
You want to find two numbers that are
compatible with the number 7. A compatible
number is CLOSE to 52, one bigger and one
smaller than 52. It is also a multiple of 7.

3. Use division facts for 7 and patterns to
find nearby compatible numbers for
528. The compatible numbers are
MULTIPLES of 7, which make them easy
to work with!
490 ÷ 7 = 70, 49 is smaller than 52
560 ÷ 7 = 80, 56 is larger than 52
The answer is between 70 and 80.
Compatible Numbers
7
14
21
28
35
42
49
56
63
70
77
84
Multiples of 752

4. 252 ÷ 3
Look at first two digits: 252
The divisor is 3:
240 ÷ 3 = 80
252 ÷ 3 =
270 ÷ 3 = 90
The best estimate is between 80 and 90.
3
6
9
12
15
18
21
24
27
30
33
3625

5. 368 ÷ 6
Look at first two digits: 368
The divisor is 6:
360 ÷ 6 = 60
The best estimate is 60.
**Sometimes there is only one compatible
number.

6. 3150 ÷ 9
Look at first two digits: 3150
The divisor is 9:
2700 ÷ 9 = 300
3150 ÷ 9 =
3600 ÷ 9 = 400
The best estimate is between 80 and 90.

7. 4000 ÷ 7
Look at first two digits: 4000
The divisor is 7:
3500 ÷ 7 = 500
4000 ÷ 7 =
4200 ÷ 7 = 600
The best estimate is between 500 and 600.

8. 440 ÷ 8
Look at first two digits: 440
The divisor is 8:
400 ÷ 8 = 50
440 ÷ 8 =
480 ÷ 8 = 60
The best estimate is between 50 and 60.