Chapter 2 Estimation and Number Theory

Question 1

Which is the closest estimate of 88 X 41 (rounding)?

Accepted Answer

90 X 40

Question 2

What is the sum of all the factors of 18?

Accepted Answer

39

Question 3

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

Accepted Answer

30

Question 4

What is the least common multiple of 6 and 9?

Accepted Answer

18

Question 5

These are some of the multiples of which number: 3, 6, 9, 15, 18?

Accepted Answer

3

Question 6

What is the greatest common factor of 20 and 35?

Accepted Answer

5

Question 7

These are the factors of which number: 1, 2, 3, 4, 6, 8, 12, 24?

Accepted Answer

24

Question 8

Which statement is incorrect?

Accepted Answer

3 is a common factor of 11 and 17

Question 9

What is the estimated quotient 638 ÷ 8 ?

Accepted Answer

80

Question 10

What is the estimated product 579 X 6

Accepted Answer

3,600

Question 11

Which pair of numbers has 10 as a common factor?

Accepted Answer

10 and 20

Questions 11