Estimating Operations with Decimals TeacherTwins©2015

Warm Up Guess Estimation Based on little or no evidence Possible Answers Guess Estimation Based on little or no evidence Not the real answer Educated Guess

Flippable

Estimating Addition and Subtraction of Decimals A common way to estimate when adding and subtracting decimals is to round each number. Example1: Kim bought a shirt for $14.78, a scarf for $9.20 and a belt for $12.35. About how much money did she spend? $14.78 rounds to $15.00 $9.20 rounds to $9.00 $12.35 rounds to $12.00 Kim spent about $ 36.00

Practice Estimate each problem. 1). 3.92 + 6.48 2). 6.97 – 2.39 3). Kelly ran 4.35 miles on Monday, 3.67 miles on Tuesday and 3.8 miles on Friday. About how many miles did she run during the week? 4 + 6 =10 7-2=5 4 + 4+ 4= 12 miles

 

This is one possible answer.     This is one possible answer. This is one possible answer.  

These are possible answers.   These are possible answers. 570 + 35 = 605 790-3 = 787 34 x 10= 340   No, 5 x 5 =25

Closure Give an example of a time when it would be helpful to estimate.