What's the Problem?

To find 4 times any number, Susan uses the Double-Double strategy (multiply by 2, then by 2 again). Susan wrote (2x9) x 2 to record how she would solve 4x9.

What is 4x9?

What is another way to solve 4x9?

To find 5 times any number, Kaylee first multiplies by 10 and then finds half the product.

a) Write an expression with parenthesis to show how Kaylee would solve 7x5.

b) What is 7x5?

c) What is another way to solve 7x5?

When given any number times 9, Jasper multiplies the number by 10 and then removes one group of the number.

a) Write an expression with parenthesis to show how Jasper would solve 3x9.

b) What is 3x9?

c) What is another way to think about 3x9?

Brayden loves multiplying by 8 because he can double-double-double.

a) Write an expression with parenthesis to show how Brayden would solve 8x7.

b) What is 8x7?

c) What is another way to think about 8 x 7?

Jonah was asked to add 4 and 7 then multiply the sum by 9. Which expression shows Jonah's problem? (The sum is the answer to an addition problem).

• (4+7) x 9

• (7-4) x 9

• 4 + (7x9)

Patrick needed to multiply 4 and 6 then subtract 12 from the product. Write an expression with parentheses to show the problem. (The product is the answer to a multiplication problem).

Violet divided 81 by 9 then multiplied the quotient by 3. Write an expression with parentheses to show the problem. (The quotient is the answer to a division problem).

54- (3x8)

(a)  

(28  $\div$  7) x 4

(a)  

Challenge: Rafael was given the problem 44 x 9. Write an expression to show how you would solve the problem.