Estimation Strategies — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A box of 48 markers costs $12.79. About how much do 6 boxes cost when estimating with whole dollars?
A) About $78
B) About $120
C) About $90
D) About $48
$12.79 rounds to $13, and 13 times 6 equals $78, the closest estimate to $78.
2. Maya runs 2.85 miles per day for 21 days. About how many miles does she run total?
A) About 6
B) About 60
C) About 600
D) About 6000
About 3 miles times about 20 days gives 60, the right order of magnitude.
3. A recipe needs 0.75 cup of sugar. For 19 batches, about how much sugar is needed?
A) About 1 cup
B) About 5 cups
C) About 15 cups
D) About 100 cups
About 0.75 times 20 equals 15, so roughly 15 cups is the closest estimate.
4. Ben has $50 and buys items priced $9.95, $14.20, and $4.80. About how much change?
A) About $5
B) About $10
C) About $15
D) About $21
$10 plus $14 plus $5 equals $29, and $50 minus $29 leaves about $21.
Part B: Fill in the Blank
Write the correct answer on each line.
1. A truck carries 28 boxes weighing 19.5 lb each. Estimated total weight is about 600 lb.
About 30 boxes times about 20 lb equals 600, a close total weight estimate.
2. A class of 32 students each pays $4.85 for a trip. Estimated total is about $150.
About 30 students times about $5 equals $150, a quick reasonable total estimate.
3. A car travels 312 miles on 11.8 gallons. Estimated miles per gallon is about 30.
About 300 miles divided by about 10 gallons equals 30 miles per gallon.
4. A baker uses 0.45 lb of flour per loaf for 22 loaves. Estimated flour is about 10 lb.
About 0.5 lb times about 20 loaves equals 10 lb, a close total estimate.
5. Tickets cost $18.95 each for 41 students. Estimated total cost is about $800.
$20 times 40 equals $800, a quick and close estimate of total cost.