Who knows why math is so easy for some people yet so much more difficult for others? For those who are challenged by simple math problems the difficulties can seem unconquerable. But, if you give children a different route to take you’ll often find that they can finally comprehend and rapidly improve in math. Take subtraction, for example. When first learning to subtract double-digits or larger numbers kids can often get confused about borrowing. When you start explaining to the children that you’ll be borrowing from the “tens” to subtract the “ones”, and that you’ll be borrowing from the “hundreds” to subtract the “tens”, you’ll often begin to see the glazing come over their eyes.
There is a much easier way to get kids to learn how to subtract large numbers from other large numbers. Write down the number “501” and subtract from it the number “397”. As you can see, the “9” and the “7” are larger than the “0” and the “1” so you’ll have to borrow. Instead of going over to the “5”, and crossing it out, replacing it with a “4” and doing all the steps to the normal subtraction process, make it much easier on the child:
Instruct the child to look at the “5” minus the “3”. He knows, of course, that it will leave “2” remaining. Before writing the “2” down, though, look to the next column. Will you need to borrow? If the answer is “no” go ahead and write down the “2”. If you do have to borrow, as in this case, write the next lowest number: “1”. When you do this you have borrowed. Make a tiny “1” in front of the “0” so that you can remember that the number is now “10” instead of “0” because you borrowed. It can be helpful, while the child is learning, to circle the tiny “1” and the “0” together so the child remembers that the number is now “10”.
Have the child look at the second column now. “10” minus “9” is “1”. Before writing down the “1” look at the last column. Will you need to borrow? If not, write down the “1”. If you do need to borrow, as in this case, write the next lowest number: “0”. Remember to make the tiny “1” next to the “1” in the “501”, and to encircle the two “1’s”, if needed. Now all that’s left to do is to subtract “7” from “11”.
Kids can do even the most complicated subtraction problems when they use the left-to-right technique rather than the right-to-left method often taught in schools. Have them practice the left-to-right technique a few times; you’ll be surprised at how quickly they learn it!
Another subtraction tip involves subtracting 7’s, 8’s and 9’s. Take the “9’s”, for instance. Many kids will find it much easier to take away “10” and then add “1” when subtracting in their heads. The same goes for the “8’s” or “7’s”. Since kids easily learn how to add and subtract by “10” they often find it simpler to subtract “10” and then add the “1”, “2” or “3” needed to make the difference between the “10” and the number they’re actually subtracting. Have your child practice this technique and soon he or she will be able to subtract numbers which aren’t too large in their heads. Kids will rapidly improve if you spend just a short amount of time teaching them how to do subtraction shortcuts that really help!
