Decimals

The times for Erin’s five laps around the track were 56.6 seconds, 57.9 seconds, 57.5 seconds, 65.3 seconds, and 65.7 seconds. Using rounding to the nearest whole second as the only estimation technique, what is the total estimated time for Erin’s five laps in seconds?

• 300

• 303

• 304

• 320

What is the difference of –89.16 – 154.81?

• -243.97

• -65.65

• 65.65

• 243.97

Jose's mother gave him $10 to go buy groceries. He picked up a gallon of milk for $3.49, three pounds of oranges that cost $1.14 per pound, and a box of cereal for $3.46. Shen used front-end estimation to determine whether he had enough money for the groceries. How much did he estimate the total cost would be?

• He estimated that he had about $7 worth of groceries.

• He estimated that he had about $9 worth of groceries.

• He estimated that he had about $10.30 worth of groceries.

• He estimated that he had about $10.40 worth of groceries

Seema used compatible numbers to estimate the product of (–25.31)(9.61). What was her estimate?

• -250

• -240

• 240

• 250

• (1.6)(3) – (1.6)(0.1)

• (–1)(3) + (–0.6)(0.1)

• (1)(3) – (0.6)(0.1)

• (–1.6)(3) + (–1.6)(0.1)

Oranges were on sale for $0.45 per pound. Leo bought 12.6 pounds. Which expression shows how to determine the total cost of the oranges?

• 12.6 x 0.45

• 12.6 - 0.45

• 12.6 + 0.45

• 12.6/0.45

What is the product of (–0.9)(–2.4)?

• -3.3

• -2.16

• 2.16

• 3.3

Chi needs to simplify the expression below.

(1.25 - 0.4) / 7 + 4 x 3

Which operation should she perform first?

• addition

• subtraction

• multiplication

• division

3(8 - 4) + 2 x 5.5