Multiplying 2-Digit Numbers: Techniques and Strategies

What is the first step in estimating the product of 28 and 18?

• Subtract 18 from 28

• Round 28 to 30 and 18 to 20

• Add 28 and 18

• Multiply 28 by 18 directly

Tags

CCSS.4.NBT.B.5

When multiplying 28 by 18, what is the result of 28 times 8?

• 224

• 280

• 64

• 16

Why is the answer 504 considered reasonable for the product of 28 and 18?

• It is more than 700

• It is close to the estimate of 600

• It is less than 500

• It is exactly 600

Tags

CCSS.3.NBT.A.3

What is the product of 3 times 40?

• 30

• 400

• 12

• 120

Tags

CCSS.4.NBT.B.5

What is the product of 3 times 400?

• 300

• 120

• 400

• 1200

Tags

CCSS.4.NBT.B.5

What is the estimated product of 126 and 52?

• 6000

• 7000

• 8000

• 5000

Tags

CCSS.4.NBT.B.5

What is the result of multiplying 126 by 2?

• 126

• 252

• 504

• 630

Tags

CCSS.4.NBT.B.5

What is the result of multiplying 126 by 5 tens?

• 3150

• 1260

• 630

• 6300

Tags

CCSS.4.NBT.B.5

Why did the product of 126 and 5 tens have a zero in the ones place?

• Because 126 times 5 tens is 6300

• Because 126 times 5 is 630

• Because 126 times 5 tens is 3150

• Because 126 times 5 is 1260

Tags

CCSS.4.NBT.B.5

What is the closer estimate for the product of 126 and 52?

• 6500

• 5000

• 7000

• 6000

Tags

CCSS.4.NBT.B.5