Estimating Numbers to Make Compatible Numbers

Use compatible numbers. Estimate to find the sum. 
34+83=

• 110

• 117

• 98

• 100

Use compatible numbers. Estimate to find the sum. 
124 + 149=

• 300

• 275

• 273

• 175

Use compatible numbers. Estimate to find the sum. 
15 + 39=

• 54

• 68

• 57

• 55

Use compatible numbers. Estimate to find the sum. 
205 + 582=

• 787

• 785

• 834

• 700

A school bought 722 packages of glow sticks for a party. Each package contained 6 glow sticks. What is the best estimate of the number of glow sticks purchased by the school?

Hint: Round the packages of glow sticks to the tens place**

• 120

• 4,320

• 100

• 4,000

Use compatible numbers to solve. 
287/42=?

• 7

• 70

• 8

• 80

Use compatible numbers. Estimate to find the sum. 
63 + 127=

• 170

• 100

• 185

• 250

Use compatible numbers. Estimate to find the sum. 
377 + 429=

• 805

• 700

• 750

• 825

Which division problem shows the best way to estimate 715 ÷ 9 using compatible numbers?

• 700 ÷ 10

• 720 ÷ 9

• 630 ÷ 9

Which division problem shows the best way to estimate 39 ÷ 5 using compatible numbers?

• 40 ÷ 5

• 36 ÷ 6

• 35 ÷ 5