M2L15 Decimal Multiplication: Making Sense of Numbers

Multiple Choice

Which of the following is a reason estimation is useful when multiplying decimals?

• It helps verify the reasonableness of answers.

• It always gives the exact answer.

• It makes calculations more complicated.

• It is not needed for decimal multiplication.

Multiple Choice

Which step is necessary after multiplying decimals as if they were whole numbers?

• Place the decimal point in the product

• Divide the product by 10

• Add the decimal places of the factors

• Round the product to the nearest whole number

Multiple Choice

Why is estimation useful when checking the placement of the decimal point in a product?

• It makes the calculation faster

• It always gives the exact answer

• It helps verify if the answer is reasonable

• It avoids the need for multiplication

Multiple Select

Select all the statements that are true about multiplying decimals.

• You ignore decimal points and multiply as whole numbers first

• The product has as many decimal places as the sum of the decimal places in the factors

• You always round the product to the nearest whole number

• Estimation can help check if the decimal placement is reasonable

Multiple Choice

Which of the following statements about decimals is correct?

• Zeros at the end of decimals change the value.

• When estimating, always use exact numbers.

• Line up decimal points when adding or subtracting decimals.

• The number of decimal places in the product is always the same as in the factors.

Multiple Choice

How do you treat the numbers when multiplying decimals initially?

• As fractions

• As whole numbers

• As percentages

• As mixed numbers

Multiple Choice

If you multiply 4.123 (three decimal places) by 5.6 (one decimal place), how many decimal places should the product have?

• 2 decimal places

• 3 decimal places

• 4 decimal places

• 5 decimal places

Multiple Choice

p 195 #1 which is a reasonable estimate for

15 x 3.8

• 60
• 80
• 70
• 50

Math Response

p 195 #5

insert the decimal point in the product to make the equation true

6.7x4.1=2727

Type answer here

Correct Answer: 27.27

Deg^°

Rad

Math Response

p 195 #6

insert the decimal point in the product to make the equation true.

13.4x3.06=41004

Type answer here

Correct Answer: 41.004

Deg^°

Rad

Math Response

p 195 #9

20x3.73=

Type answer here

Correct Answer: 74.6

Deg^°

Rad

Multiple Choice

What is the total cost of 2.2 pounds of chicken at $4.50 per pound?

• $9.90

• $10.00

• $9.00

• $8.80

Math Response

If you buy 0.5 pounds of chocolate at $8.00 per pound, how much will you spend? $___

Type answer here

Correct Answer: 4.00

Deg^°

Rad

Math Response

What is the total price for 6 pounds of sugar at $1.25 per pound?$___

Type answer here

Correct Answer: 7.50

Deg^°

Rad

Drag and Drop

You will spend

Placeholder

on 4 pounds of vegetables at $2.75 per pound.

Drag these tiles and drop them in the correct blank above

$11.00

$10.00

$12.00

$11.50

Math Response

What is the total cost of 1.8 pounds of beef at $9.00 per pound?___

Type answer here

Correct Answer: 16.20

Deg^°

Rad

Multiple Choice

What does a standard algorithm refer to?

• A random guess

• A traditional step-by-step method for solving math problems

• A type of graph

• A computer program

Multiple Choice

Which of the following is NOT a decimal?

• 0.75

• 1.25

• 3/4

• 2.5

Multiple Choice

Which of the following is NOT an estimate?

• About 10 miles

• Exactly 5 apples

• Nearly 100 people

• Roughly 20 minutes

Math Response

p 196 #16

A race is 6.21 miles long. Adesh runs at a constant rate of 1 mile every 9.5 minutes. At that rate how long will it take Adesh to run the race? ___minutes

Type answer here

Correct Answer: 58.995

Deg^°

Rad

Math Response

p 197 #17

A trainer at a gym earns $2,456.75 every month. She earns an extra $4.75 every time she sells a gym membership. Last month, the trainer sold 32 gym memberships. What is the total amount

of money the trainer earned last month? $______

Type answer here

Correct Answer: 2608.75

Deg^°

Rad

Math Response

p 197 #18

Kayla wants to buy an art set that costs $58.50. Kayla has saved 80% of the amount she needs to buy the art set. How much money has Kayla saved? $_____

Type answer here

Correct Answer: 46.80

Deg^°

Rad

Dropdown

The estimated product of 19 and 3 is

Select answer

Math Response

What is the result of rounding 18.6 to the nearest whole number?

Type answer here

Correct Answer: 19

Deg^°

Rad

Multiple Choice

Jennifer bought 3.4 pounds of apples. She paid $.89 per pound.  How much did Jennifer pay for the apples?

(Round to the nearest hundreths.)

• $3.00
• $3.04
• $3.01
• $3.03

Dropdown

Big Money Mario bought a steak that weighs 1.4 pounds. The price is $12.50 per pound. How much does the steak cost?

Select answer

Multiple Choice

Amina estimate 7.8 x 4.5 = 40. Is her answer reasonable?

• YES

• NO