Estimation
Rounding
Factors
Multiples
Prime/Composite
100

What should you do when you see the word ‘about’ in directions?

Estimate

100

How would you round 68x41?

70x40

100

What are the factors of 12?

1, 2, 3, 4, 6, 12

100

What are the first 5 multiples of 4?

4, 8, 12, 16, 20

100

True or false, 31 is a prime number

True

200

What word tells you if you need an exact answer or an estimate?

About

200

Round 2,657 to the nearest hundred.

2,700

200

Is 3 a common factor of 18 and 24?

Yes

200

What is the least common multiple of 6 and 8?

24

200

True or false, 45 is a composite number

True

300

What is the estimated quotient of 321 divided by 8

40

300

What is 43,293 rounded to the nearest hundred?

43,300

300

What are two common factors of 20?

1, 2, 4, 5, 10, or 20

300

What is the sum of the first two multiples of 6?

18

300

Are 3, 9, and 18 all composite numbers?

No

400

How would you estimate to check that your answer is reasonable in the problem 389x7=2,723

400x7=2,800

400

What is 225,298 rounded to the nearest hundred thousand?

200,000

400

What is the greatest common factor of 15 and 21?

3

400

What is the least common multiple of 7 and 9?

63

400

Is 70 a prime number?

No

500

Round each number to the nearest hundred. What is the estimate of 2,892+1,931

4,800

500

Rounding to the nearest hundred thousand, what is the sum of 481,327+225,298

700,000

500

What is the sum of all the factors of 21?

32

500

What is the sum of the first 6 multiples of 5?

105

500

What are two prime numbers between 32 and 48?

37, 41, 43, 47