Arithmetic Grade Four

Lesson Fifty-seven: Rounding and Multiplying

Rounding to the Nearest Hundred: 

   If the digit in the tens column is 5 or greater, round up.
          
   If the digit in the tens column is 4 or less, round down.

      EXAMPLES:

       828  -->  800	851  -->  900       884  -->  900

     1233  -->  1200   3519  -->  3500     3499  -->  3500
Here are some problems were we are asked to first round to the nearest hundred and then multiply: 

  1)   4321 x 78
       ROUND TO NEAREST HUNDRED: 4300 x 100
       MULTIPLY:  4300 x 100 = 430000

  2)   775 x 89
       ROUND TO NEAREST TEN: 800 x 100
       MULTIPLY:  800 x 100 = 80000
You get to try a few for yourself on the next page.

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