Common Core Mystery Problem #1

Aug 20, 2015 | Sioux Falls

Recently, we've seen multiple posts online about Common Core math problems, and how parents are unable to figure out how to solve these problems. 

To help with this, we've decided to write a couple blog posts, which will hopefully help you, as the parent, to understand math the way your children are being taught in the classroom. The objective of these posts is not to share our opinions on Common Core, but just to help you understand how these problems are being completed.

Here is today's Common Core Mystery Problem #1.

Looking at the problem, 53 + 37, most of you will probably solve this problem the "Old Math" way.

Your first step would be to line the problem up vertically, and then add 3 plus 7, which would equal 10. Then you would carry the 1 above the 5 and add 5 plus 3 plus 1, which would give you 9. So, your answer would be 90.

Here is how the "New Math" way teaches your children to do it.

  1. First, they would keep the problem written horizontally instead of vertically. 
  2. The second step would be to de-construct the 37 into as many 5's and 10's as they can. Here, they decided to break 37 down to 10 plus 10 plus 10 plus 5 plus 2. (Adding these back together, you would get 37.)
  3. The third step is to start at 53, and add these deconstructed numbers on to the 53. So:
    1. 53 plus 5 equals 58
    2. 58 plus 2 equals 60
    3. 60 plus 10 equals 70
    4. 70 plus 10 equals 80
    5. 80 plus 10 equals 90

​​Both strategies will get you to the same answer. The "Old Math" way focuses on a technique called carrying, while the "New Math" way focuses on deconstructing numbers and then using those numbers to build to your answer.

This is just the first of many problems we hope to post about. If you have a specific problem you would like discussed, please feel free to e-mail it to me at [email protected].

As always, we're here to help your child with any of these and other math problems they may not be able to understand.

Hope this was helpful!