Estimating Sums
and Differences
Estimating Products and Quotients
Factors
GCF
Prime vs. Composite
100
Estimate 4,287 + 3,755 by rounding to the nearest thousand.
4,000 + 4,000 = 8,000
100
Solve 77 x 5. Then estimate by rounding.
77x5=385 and 80x5=400
100
List all the factors of 18.
1, 2, 3, 6, 9, 18
100
Find the GCF of 12 and 18.
6
100
Is 3 prime or composite?
prime (1, 3 only)
200
Solve 4,287 + 3,755. Then estimate by using front-end estimation.
4,287+3,755=8,042 and 4,000+3,000=7,000
200
Estimate 68 x 4 by using front-end estimation.
60 x 4 = 240
200
List all the factors of 28.
1, 2, 4, 7, 14, 28
200
Find the GCF of 12 and 24.
12
200
Is 15 prime or composite?
composite (1, 3, 5, 15)
300
Solve 4,287 - 3,755. Then estimate by using front-end estimation.
4,287-3,755=532 and 4,000-3,000=1,000
300
Solve 83 ÷ 2. Then give the best estimate.
83÷2=41r1 and 80÷2=40
300
List all the factors of 30.
1, 2, 3, 5, 6, 10, 15, 30
300
Find the GCF of 30 and 32.
2
300
Is 35 prime or composite?
composite (1, 5, 7, 35)
400
Estimate 4,287 - 1,265 by rounding to the nearest thousand.
4,000-1,000=3,000
400
Solve 41 ÷ 3. Then give the best estimate.
41÷3=13r2 and 30÷3=10
400
List all the factors of 42.
1, 2, 3, 6, 7, 14, 21, 42
400
Find the GCF of 28 and 42.
14
400
Is 37 prime or composite?
prime (1, 37 only)
500
Solve 55,839 + 39,322. Then estimate by rounding to the nearest ten thousand.
55,839+39,322=95,161 and 60,000+40,000=100,000
500
Estimate 357 x 6 by rounding to the nearest hundred.
400 x 6 = 2,400
500
Find all the factors of 56.
1, 2, 4, 7, 8, 14, 28, 56
500
Find the GCF of 18 and 42.
6
500
Is 93 prime or composite?
composite (1, 3, 31, 93)
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