6-1 Multiplying by 10,100, or 1000

6-1 Multiplying by 10,100, or 1000

6-2 Estimating Products

6-3 Number Sense: Decimal Multiplication

6-5 Multiplying a Decimal by a Whole #

6-6 Multiplying 2 Decimals

100

4.23 x 10 =

42.3

100

Estimate the product: 9.02 x 80 =

720 (9. x 80)

100

Use Number Sense to place the decimal point appropriately. 5.01 x 3 = 1503

15.03

100

Calculate the product: 56 x 0.4 =

22.4

100

Calculate the product: 3.5 x 0.4 =

1.4

200

19.212 x 100 =

1,921.2

200

Estimate the product: 0.54 x 36 =

18 (.5 x 36)

200

Use Number Sense to place the decimal point appropriately. 0.9 x 0.9 =

.81

200

Calculate the product: 64.2 x 20 =

1,284

200

Calculate the product: 0.06 x 15 =

0.9

300

.0867 x 1000 =

86.7

300

Estimate the product: 99.2 x 82 =

8,000 (100 x 80)

300

Correct or Incorrect: 0.05 x 12.4 = 6.2 Explain why or why not.

Incorrect; b/c it's 0.62 (You are taking a small fraction of 12.4, less than 1/2 even.)

300

Calculate the product: 0.3 x 99 =

29.7

300

Calculate the product: 0.28 x 3.7 =

1.036

400

Anya needs to buy 100 lbs. of chocolate to make her holiday truffles. If chocolate sells for $0.49 per pound, how much will Anya spend?

$49

400

Estimate using Compatible Numbers: 47.2 x 93 =

45,000 (50 x 90)

400

Complete the product and place the decimal point where it should be. 7.8 x 0.1 =

0.78

400

Leslie and her friend eat lunch at a restaurant. To determine how much money to leave as a tip she multiplies the bill by 0.18 How much money should she leave as a tip if the bill is $25?

$4.50

400

Explain how you know the number of decimal places that should be in the product when you multiply two decimal numbers together.

The total number of decimal places in the numbers being multiplied is the number of decimal places in the product.

500

Jason saved $0.02 each day for 10,000 days. How much did he save in all?

$200

500

Georgia roller skates 0.43 miles around her block each day. If she roller skated 279 days in 2006, about how many miles did she roller skate?

120 miles (.4 x 300)

500

Complete the operation and Explain why you placed the decimal where you did.
12.4 x 3.1 =

38.44 ; The decimal goes after the 8 because 12 x 3 = 36 and 38 is pretty close to 36, while 384.4 and 3.844 are way off.

500

Calculate the product: 42.6 x 15

639

500

The product of 4.7 and 6.5 is 30.55. What is the product of 4.7 and 0.65? What is the product of 4.7 and 65?

4.7 x 0.65 = 3.055
4.7 x 65 = 305.5