Rounding

8/18/2013

 
Last year, I developed a new strategy for teaching rounding that seemed to help more students remember the steps.  Here is an example:
Round 32,759 to the hundreds' place:
Underline the digit to be rounded: 32,759
7's boss, 5, is looking over his shoulder to see if he is working.  Since 5 is a big boss (5-9 are big bosses), he has the authority to give raises.  He gives 7 a raise, so he is now worth 8.  All numbers in front (32) get copied, and all numbers behind (59), become zeros.
32,759
copy +1 turn to zeros
32,800
Little bosses cannot give raises, so if 5 had been a 4, 7 would have no raise.  32,759
                                                  copy +0 turn to zeros
                                                   
32,700
 



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