Compatible numbers
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Transcript of Compatible numbers
Estimating QuotientsUsing Compatible Numbers
Compatible Numbers
To find compatible numbers, look at the first two numbers in the dividend (the larger number in your division problem).
528 ÷ 7You 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.
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 71421283542495663707784
Multipl
es o
f 7
52
252 ÷ 3
Look at first two digits: 252The divisor is 3:
240 ÷ 3 = 80252 ÷ 3 =
270 ÷ 3 = 90
The best estimate is between 80 and 90.
369121518212427303336
25
368 ÷ 6
Look at first two digits: 368The divisor is 6:360 ÷ 6 = 60
The best estimate is 60.
**Sometimes there is only one compatible number.
3150 ÷ 9
Look at first two digits: 3150The divisor is 9:2700 ÷ 9 = 300
3150 ÷ 9 =3600 ÷ 9 = 400
The best estimate is between 80 and 90.
4000 ÷ 7
Look at first two digits: 4000The divisor is 7:3500 ÷ 7 = 500
4000 ÷ 7 =4200 ÷ 7 = 600
The best estimate is between 500 and 600.
440 ÷ 8
Look at first two digits: 440The divisor is 8:400 ÷ 8 = 50440 ÷ 8 =
480 ÷ 8 = 60
The best estimate is between 50 and 60.