1. Lesson 5 -1:

2. A benchmark is a number that is easy to use when you estimate. When estimating the sums and differences of fractions, we use the benchmarks 0, ½, and 1. (another chart on page 249 in textbook)

3.  Change each fraction to 0, ½, or 1.  Add or subtract. 5 11 + 3 25 + ½ 0= ½

4. + 7 15 4 9 + ½ ½ = 1

5.  If you have mixed numbers, then round the fraction part up to 1 or down to 0.  If the fraction is greater than ½, then round up to 1.  If it is less than ½, then round down to 0.

6. 3 4 1510 1 8 16 10 = 6