Estimate Sums and Differences

Directions: Estimate the sum or difference of each problem. 

Problem:

                        58

    -  16 

Solution
Step 1:           Round to the nearest ten 

                            58

   -  16

  Rounding 58 gives 60

  Rounding 16 gives 20

Solution
Step 2:           Subtract the tens.

                             60

   -  20

                                   40