5th Grade Multiplication Review

Doubling & Halving

100

18 x 3

18 x 3 = 9 x 6 = 54

200

36 x 50

36 x 50 = 18 x 100 = 1,800

300

35 x 14

35 x 14 = 70 x 7 = 490

400

45 x 24

45 x 24 = 90 x 12 = 180 x 6 = 360 x 3 = 1,080

500

360 x 50

360 x 50 = 180 x 100 = 18,000

Estimation

100

Estimate your answer to this problem: 57 ➗ 3

Explain why.

Explanations vary. Correct answer: 19

200

Estimate your answer to this problem: 340 ➗ 5

Explain why.

Explanations vary. Correct answer: 68

300

Estimate your answer to this problem: 132 ➗ 12

Explain why.

Explanations vary. Correct answer: 11

400

Estimate your answer to this problem: 234 ➗ 18

Explain why.

Explanations vary. Correct answer: 13

500

Estimate your answer to this problem: 923 ➗ 71

Explain why.

Explanations vary. Correct answer: 13

Standard Algorithm

100

64 x 21

1,344

200

31 x 28

868

300

312 x 14

4,368

400

558 x 22

12,276

500

903  x 74

66,822

Random

100

Ms. Molzan is making brownies (yes, this time they're REAL brownies). Each batch of brownies costs $3.25 to make. Use a ratio table to find the cost to make 9 batches.

See image from Ms. Molzan

200

Ms. Molzan is making brownies (yes, this time they're REAL brownies). Each batch of brownies costs $3.25 to make. Use a ratio table to find how many batches of brownies Ms. Molzan can make for $276.25.

See image from Ms. Molzan

300

1/4 x 16 =____, so 25 x 16 =____

4 ; 400

400

3/4 of 64 is____, so 75 x 64 is____.

48 ;  4,800

500

True or False: 180 x 20 = 36,000 ➗ 10

True

180 x 20 = 3,600

36,000 ➗ 10 = 3,600