New Vocabulary VocabularyDefinitionUsing symbols productThe answer to a multiplication problem 2 x 4 = 8 product Multiplying Decimals
Example: Science Application Something that weighs 1 lb on Earth weighs 0.17 lb on the Moon. How much would a 4 lb dumbbell weigh on the Moon? Multiply 4 by 0.17, since 1 pound on Earth is 0.17 pound on the Moon. 17 4 68 Multiply as you would with whole numbers. 4 0.17 Multiplying Decimals
Example Continued Something that weighs 1 lb on Earth weighs 0.17 lb on the Moon. How much would a 4 lb dumbbell weigh on the Moon? 0.17 Place the decimal point by adding the number of decimal places in the numbers multiplied. A 4 lb dumbbell on Earth weighs 0.68 lb on the Moon. 2 decimal places + 0 decimal places 2 decimal places Multiplying Decimals
Check It Out Something that weighs 1 lb on Earth weighs 0.17 lb on the Moon. How much would a 7 lb dumbbell weigh on the Moon? 7 × 0.17 = 1.19 lb Multiplying Decimals
You can use a decimal grid to model multiplication of decimals. Helpful Hint Multiplying Decimals
Example: Multiplying a Decimal by a Decimal Find the product. 0.3 0.4 Multiply. Then place the decimal point 1 decimal place + 1 decimal place2 decimal places 0.12 Multiplying Decimals
Example: Multiplying a Decimal by a Decimal 0.07 0.8 Multiply. Then place the decimal point decimal places + 1 decimal place3 decimal places; use a placeholder zero Estimate the product. 0.8 is close to 1 = is close to the estimate of The answer is reasonable. Multiplying Decimals
Example: Multiplying a Decimal by a Decimal 1.34 2.5 Multiply. Then place the decimal point 2 decimal places + 1 decimal place3 decimal places 670 Estimate the product. Round each factor to the nearest whole number. 1 3 = is close to the estimate of 3. The answer is reasonable Multiplying Decimals
Check It Out Find the product × = Multiplying Decimals
1. Identify the product 0.01 A B C D Student Response Systems Multiplying Decimals
5. Strawberry lemonade costs $0.89 per packet. Karen bought 58 packets of strawberry lemonade for a picnic. How much did she pay for it? A. $51.62 B. $51.86 C. $52.54 D. $52.93 Student Response Systems Multiplying Decimals