Estimating Sums and Differences of Fractions

Estimate the difference by replacing each fraction with 0, 1/2, or 1.

24/25 - 5/12 =

• 0

• 1/2

• 1

• 1 1/2

• 2

Estimate the difference by replacing each fraction with 0, 1/2, or 1.

24/25 - 9/10 =

• 0

• 1/2

• 1

• 1 1/2

• 2

Estimate the difference by replacing each fraction with 0, 1/2, or 1.

11/20 - 2/35 =

• 0

• 1/2

• 1

• 1 1/2

• 2

17/20 - 6/20

• 11

• 23/20

• 11/20

• 11/0

There was 7/8 of a yard of fabric left and Lisa used 6/8 of it on her Halloween costume. How much fabric is left?

• 1/8 yard

• 13/8 yards

• 2/8 yard

• Not enough information

4/15 + 11/15 =

• 15

• 15/15 or 1

• 4/15

• 15/30

Evaluate Reasonableness Hector and Veronica are going hiking. They made a trail mix that has 2/3 cup of almonds, 7/8 cup of peanuts, and 4/5 cup of raisins in it. Hector estimates that they made about 3 cups of trail mix. Is the estimate greater than or less than the actual sum? How do you know?

• The estimate is greater because each fraction is rounded up to a benchmark.

• The estimate is less because each fraction is rounded down to a benchmark.

• The estimate is greater because they really made more than 3 cups.

• The estimate is less because each fraction is rounded up to a benchmark.

9/10 - 3/8 =

• 1 1/2

• 1

• 0

• 2

• 1/2

5/8 + 2/5 =

• 1 1/2

• 1

• 0

• 2

• 1/2

6/7 + 3/5 =

• 1 1/2

• 1

• 0

• 2

• 1/2