Multiplying and Dividing: Master Mental and Written Methods

Question 1

Which of the following is NOT a strategy for estimating products?

Accepted Answer

Multiplying the numbers directly

Answer

Rounding to the nearest ten

Answer

Using compatible numbers

Answer

Multiplying by multiples of ten

Question 2

Which of the following is a mental multiplication method that involves breaking numbers into smaller parts and multiplying them?

Accepted Answer

Chunking

Answer

Grid method

Question 3

Which of the following equals 0.25?

Accepted Answer

1/4

Answer

1/2

Answer

1/8

Answer

1/10

Question 4

Given a rectangle with a width of 5 cm and an area of 40 cm². What is its length?

Accepted Answer

7 cm

Answer

6 cm

Answer

8 cm

Answer

9 cm

Question 5

Using the short division method, what is 345 ÷ 9?

Accepted Answer

38 remainder 5

Answer

35

Answer

38 remainder 7

Answer

40 remainder 3

Question 6

What is the product of 0.5 and 0.2?

Accepted Answer

0.01

Answer

0.1

Answer

1.0

Answer

10.0

Question 7

Convert the fraction 1/4 to its decimal equivalent.

Accepted Answer

0.25

Answer

0.2

Answer

0.4

Answer

0.5

Question 8

To multiply 345 by 23 mentally, which strategy should you use?

Accepted Answer

Multiply 345 by 20 and then add the product of 345 and 3

Answer

Multiply 345 by 30 and then subtract the product of 345 and 7

Answer

Multiply 345 by 2 and then multiply the result by 11.5

Answer

Multiply 345 by 23 in a single step

Question 9

Simplify 3/4 ÷ 1/2.

Accepted Answer

3/2

Answer

1/2

Answer

1/4

Answer

3/4

Question 10

Simplify the fraction 9/15.

Accepted Answer

1/3

Answer

1/4

Answer

1/5

Answer

1/6

Question 11

Find the missing number in the multiplication sequence: 1, 3, 9, ?, 81

Accepted Answer

27

Answer

18

Answer

36

Answer

45

Question 12

A rectangle has a length of 8 cm and a width of 5 cm. What is its area?

Accepted Answer

40 cm²

Answer

13 cm²

Answer

20 cm²

Answer

60 cm²

Question 13

Which of these is NOT a factor of 24?

Accepted Answer

5

Answer

2

Answer

3

Answer

8

Question 14

Which of these equations shows the distributive property?

Accepted Answer

4 * (2 + 3) = (4 * 2) + (4 * 3)

Answer

(2 + 3) * 4 = 2 * 4 + 3 * 4

Answer

4 + (2 * 3) = (4 + 2) * 3

Answer

4 * (2 - 3) = (4 * 2) - (4 * 3)

Question 15

When multiplying a whole number by a decimal, the best method is to:

Accepted Answer

Multiply as normal and then multiply the product by the number of decimal places in the second number

Answer

Ignore the decimal and multiply as normal

Answer

Multiply the two whole numbers and then add the decimal places

Answer

Divide the two numbers by their decimal places and then multiply the results

Question 16

What is the area of a square with sides measuring 6 cm?

Accepted Answer

36 cm²

Answer

12 cm²

Answer

18 cm²

Answer

24 cm²

Question 17

Using the distributive property, simplify the expression: 5(x + 2)

Accepted Answer

5x + 10

Answer

5x + 2

Answer

x + 10

Answer

10x + 2

Question 18

Select the best definition for the term 'estimate'.

Accepted Answer

A number close to the exact answer.

Answer

The precise answer to a calculation.

Answer

A number significantly lower than the exact answer.

Answer

A number that is not related to the calculation.

Question 19

If a car travels 450 miles on 15 gallons of petrol, calculate the car's miles per gallon.

Accepted Answer

25

Answer

20

Answer

30

Answer

35

Question 20

A pizza is cut into 8 equal slices. If Amy eats 3 slices, express the fraction of the pizza she ate in its simplest form.

Accepted Answer

1/4

Answer

1/2

Answer

1/3

Answer

1/8

Question 21

Find one-quarter of 28.

Accepted Answer

7

Answer

6

Answer

8

Answer

9

Question 22

What is the most efficient way to mentally calculate 35 x 4?

Accepted Answer

Double 35 and then double the result.

Answer

Multiply 35 by 4, carrying over when necessary.

Answer

Multiply 35 by 10 and then divide by 2.5.

Answer

Add 35 four times.

Question 23

A baker needs to divide 24 cupcakes evenly among 6 boxes. How many cupcakes will be in each box?

Accepted Answer

4

Answer

12

Answer

6

Answer

3

Question 24

Which calculation gives the same answer as 12.5 x 4?

Accepted Answer

125 x 0.4

Answer

1250 x 0.04

Answer

1.25 x 40

Answer

12.5 x 0.04

Question 25

A recipe requires 2/3 cup of flour. If you want to make half the recipe, how much flour will you need?

Accepted Answer

1/3 cup

Answer

1 cup

Answer

1/6 cup

Answer

4/3 cup

Question 26

What is the missing number in the equation: 3.5 x ___ = 105?

Accepted Answer

30

Answer

3

Answer

10

Question 27

Which of these is the most efficient way to calculate 25 x 16?

Accepted Answer

Multiply 25 by 4 and then multiply the result by 4.

Answer

Use the standard written multiplication method.

Answer

Add 25 sixteen times.

Question 28

A group of 15 friends wants to share 45 pieces of candy equally. How many pieces will each friend get?

Accepted Answer

3

Answer

60

Answer

5

Answer

15

Question 29

What is the value of 1/4 divided by 2?

Accepted Answer

1/8

Answer

2/4

Answer

1/2

Question 30

Which of the following calculations will result in a number greater than 100?

Accepted Answer

12.5 x 8

Answer

50 x 1.5

Answer

75 / 1.5

Answer

25 x 3.5

Question 31

A rectangular garden is 15 meters long and 8 meters wide. What is the area of the garden?

Accepted Answer

120 square meters

Answer

120 meters

Answer

240 square meters

Answer

23 meters

Question 32

A bakery makes 240 cakes each day. They sell the cakes in boxes of 12. How many boxes of cakes do they need to pack all the cakes?

Accepted Answer

20

Answer

12

Answer

24

Answer

30

Question 33

What is the product of 3.5 and 4?

Accepted Answer

14

Answer

12.5

Answer

10.5

Answer

7

Question 34

Which of the following is the result of 45 divided by 0.5?

Accepted Answer

90

Answer

22.5

Answer

180

Answer

40.5

Question 35

A recipe for 6 people requires 2/3 cup of flour. How much flour is needed for 18 people?

Accepted Answer

1 cup

Answer

3 cups

Answer

1 1/3 cups

Answer

2 cups

Question 36

What is the result of 2/5 divided by 1/3?

Accepted Answer

1 1/5

Answer

2/15

Answer

6/5

Answer

3/5

Question 37

Which of the following is equivalent to 3 x 5 x 2?

Accepted Answer

5 x 6

Answer

10 x 3

Answer

15 x 2

Answer

3 x 10

Question 38

A train travels 480 kilometers in 6 hours. What is its average speed?

Accepted Answer

80 km/h

Answer

90 km/h

Answer

60 km/h

Question 39

A rectangular garden is 12 meters long and 8 meters wide. What is the area of the garden?

Accepted Answer

96 square meters

Answer

120 square meters

Answer

20 square meters

Answer

48 square meters

Question 40

A farmer harvested 150 apples. He packed them into boxes, each holding 15 apples. How many boxes did he use?

Accepted Answer

10

Answer

20

Answer

12

Answer

15

Question 41

What is the quotient when 72 is divided by 9?

Accepted Answer

8

Answer

12

Answer

9

Answer

6