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