Powers of 10
What happens to the decimal point when you multiply 0.5 by 10?
It increase by 10 times making it 5.
What is 0.2 x 0.3? Show your work.
0.06
What is 0.6 × 4?
2.4
Sarah bought 2.5 pounds of apples at $1.20 per pound. How much did she spend?
Sarah spent $3.00
To find an appropriate value in a calculation is to...
estimate
If you multiply 0.03 by 100, where does the decimal point move?
It moves to the right two times, making the answer 3.
Calculate 0.5 x 0.4 and explain how you found your answer.
0.2; using a strategy like standard algorithm, area model, or decimal grids.
Calculate 3.2 × 10. Explain how you got your answser.
32.
Explanations may vary.
A car travels 60 miles per hour. How far will it travel in 1.5 hours?
90 miles
When multiplying by a power of 10, the __________ tells us the number of places the digits shift to the left.
exponent
Explain how multiplying 0.06 by 10 affects the number of zeros in the product.
*Answers may vary*
It moves the decimal point, thus moving the place value and adding a zero.
What is 0.6 times 0.7? Describe the strategy you used.
0.42
Strategies will vary.
A bottle holds 2.5 liters of water. How much water is in 66 bottles?
15 liters
If a bag of flour weighs 3.5 pounds and costs $4.75, how much does 3 bags cost?
3 bags would cost $14.25
When multiplying, the values placed in an area model are called...
partial products
What is 0.4 x 102?
40
Multiply 7.5 x 2.5 and explain your reasoning.
18.75
Strategy must be shown!
If a pencil costs $0.75, how much do 5 pencils cost?
$11.25
Jason runs 2.5 miles every day. How far does he run in 77 days?
192.5 miles in 77 days
A __________ gives two numbers between which acceptable values fall to find an estimate.
range
Describe the pattern in the placement of the decimal when multiplying 0.25 by 103.
Shift the decimal to the right three times, moving the place value to the left three time and making the product 1,000 times bigger than 0.25.
Answer: 250
What is 4.5 x 5.5?
24.75
If you read 1.25 books per week, how many books will you read in 88 weeks?
110 books
If a recipe calls for 0.75 cups of sugar and you want to make 4 batches, how many cups of sugar do you need?
3 cups of sugar
The answer to a multiplication problem is a _________.
product