Maureen Curran and Mary Lou Aalbers Hazelwood School District Teacher Tips Activity #2

Children should be able to decide if an answer is reasonable. One way to address this is to teach them how to estimate the value of a fraction or decimal. Example: Classify fractions and decimals as close to 0, close to 1/2 or close to /9 The numerator is very small compared to the denominator so the value is about 0 6/10 The numerator is almost half the denominator so the value of this fraction is about 1/2 8/9 The numerator is almost the same as the denominator so the value is about 1. Review these strategies for both decimals & fractions and then do this activity.

ESTIMATING SUMS of FRACTIONS & DECIMALS Give students about 40 seconds to estimate an answer for all the problems on the next slide. Number their papers from 1 to 8. Show the slide and then stop after 40 seconds so that you know they are estimating the answers in their heads. Students, Start your engines!! Is your paper numbered? Ready? (CLICK on slide and start timing..)

1. 1 3/8 + 7/ /5 = about ? / / /8 = about ? 3. 9/ /9 + 1/20 = about ? 4. 5/6 + 1/10 + 4/9 = about ? = about ? = about ? = about ? = about ? TIMES UP !!!

1. 1 3/8 + 7/ /5 = about / / /8 = about / /9 + 1/20 = about /6 + 1/10 + 4/9 = about 1 1/ = about 1/ = about = about = about 4 How did you do?