Math quiz

What is the area model of 75 x 21?

• (70 x 20) + (70 x 1) + ( 20 x 5) + (5 x 1)

• 70 + 20 + 1 + 5

• 70 x 10 x 1 x 5

• 70 - 20

  70 - 1

  20 - 5

  1 - 5

Tags

CCSS.3.MD.C.7B

CCSS.4.MD.A.3

Gabby has 57 doggy coins to spend in the bank. She had to multiply 98 more doggy coins that she had to spend in the bank. How many doggy coins did she have to spend in all? Explain.

Answer explanation

How I found the answer is that Gabby had 57 coins, then she multiplied by 98. To answer this, she figured out the area model, so she multiplied 50 x 90, which was 4,500. Then she multiplied 50 x 8, which was 400. Then she multiplied 90 x 7, which was 630. Finally, she multiplied 7 x 8, which was 56. Now she added all those partial products, and she got 5,586.

Tags

CCSS.3.MD.A.2

25 x 19

• 275

• 475

• 375

• 175

Tags

CCSS.4.NBT.B.5

What is the area model for 15 x 18?

• (10 x 10) + (10 x 8) + (10 x 5) + (5 x 8)

• Answer: 270

• Answer: 170

• 100 x 10 + 70

Tags

CCSS.3.MD.C.7B

CCSS.4.MD.A.3

What is 17 x 10?

5 x 10

Tags

CCSS.3.MD.A.2

9 x 1

Tags

CCSS.3.OA.A.1

CCSS.3.OA.C.7

8 x 7

Tags

CCSS.3.OA.C.7

7 x 2

Tags

CCSS.3.OA.A.1

CCSS.3.OA.A.3

CCSS.3.OA.C.7

8 x 3

Tags

CCSS.3.OA.A.1

CCSS.3.OA.C.7