Estimating and Multiplying Decimals

The video tutorial explains how to multiply money by focusing on decimal placement. It provides a step-by-step guide to ignoring decimals during multiplication and then placing the decimal point correctly in the result. The tutorial includes examples such as multiplying $38.52 by 8, calculating the cost of multiple pizza slices, and determining earnings based on an hourly wage. Each example emphasizes checking the reasonableness of the answer through estimation. A shortcut for multiplying money amounts by whole numbers is also introduced, highlighting the consistent movement of the decimal point.

What is the first step when multiplying a decimal number?

• Line up the decimals

• Ignore the decimal and multiply the numbers

• Add the numbers first

• Subtract the numbers first

Tags

CCSS.5.NBT.B.7

How many decimal places should be in the result of $38.52 x 8?

• Two

• One

• Three

• None

Tags

CCSS.7.EE.B.3

Why is it important to check if your answer makes sense after multiplying?

• To ensure the decimal is in the correct place

• To confirm the subtraction was accurate

• To verify the numbers were added correctly

• To make sure the numbers were divided properly

What should you do if your estimated answer is far from the actual result?

• Subtract more numbers

• Recalculate and check the decimal placement

• Add more numbers

• Ignore it

Tags

CCSS.5.NBT.B.7

In the example of $38.52 x 8, what is the estimated value used to check the answer?

• $30

• $45

• $35

• $40

Tags

CCSS.6.NS.B.3

If $1.35 is the cost of one piece of pizza, how much will 5 pieces cost?

• $7.75

• $6.75

• $5.75

• $8.75

Tags

CCSS.5.NBT.A.2

What is the result of multiplying 135 by 5 before placing the decimal?

• 540

• 270

• 1350

• 675

Tags

CCSS.5.NBT.B.7

What is the shortcut for multiplying a money amount with dollars and cents by a whole number?

• Subtract 2 from the result

• Move the decimal forward 2 places

• Move the decimal back 2 places

• Add 2 to the result

Tags

CCSS.7.EE.B.3

How much will Veronica earn if she works 12 hours at $9.85 per hour?

• $125.00

• $115.00

• $120.00

• $118.20

Tags

CCSS.5.NBT.B.7

How close is the calculated answer of $118.20 to the estimated value when multiplying $9.85 by 12?

• Very close to $120

• Very close to $130

• Very close to $110

• Very close to $100

Tags

CCSS.5.NBT.B.7