7.6 Multiply Using Mental Math

Terrance found the product for 9 x 81 like this:

9 x 81 = (9 x 80) + (9 x 1) = 720 + 9 = 729

Which strategy did he use?

• Commutative Property

• Associative Property

• Distributive Property

• Halving and Doubling

Tags

CCSS.6.NS.B.4

Eileen multiplied 40 x 88 = 3,520. Which of the following has a product of 3,520?

• 80 x 44

• 20 x 44

• 176 x 80

• 176 x 40

The Smith's are selling some of their extra chairs. They are selling 4 chairs each for $125. How much will the Smith's make if they sell all the chairs?

• $500

• $400

• $425

• $575

Tags

CCSS.3.OA.A.3

There are 42 straws in a box. Nathan bought 5 boxes. How many straws did Nathan buy?

• 220

• 110

• 210

• 120

Tags

CCSS.3.OA.A.3

MULTI- STEP: The science museum sells dinosaur models to schools and libraries for $107 each. The town library buys 3 dinosaur models. The town elementary school buys 5 models. What is the total cost of the models the town buys?

• $567

• $780

• $136

• $856

Tags

CCSS.3.OA.D.8

MULTI- STEP: Kyle and Karen each bought 5 books of ride tickets at the fair. Each book has 15 tickets. How many tickets did they buy altogether?

• 75

• 150

• 300

• 200

Tags

CCSS.3.OA.D.8

Use a strategy to find the product of 6 x 302

• 2,812

• 2,160

• 180

• 1,812

Tags

CCSS.4.NBT.B.5

Use mental math to find the unknown number:

32 x 30 = 960, so 32 x 31 = ______

• 992

• 960

• 1,024

• 982

Tags

CCSS.5.NBT.B.5