Education
How to Improve Your Speed in Math by Jimmy Cox
[Jan 30, 2008]
Hard though this may be to believe, if you use the following method for addition, you will greatly increase your speed.
Add With Complements
The basic rule for the new technique is this: To "add" over ten, subtract the complement of the larger digit from the smaller digit - and record a ten.
First we need to learn what complements are. Then we will take up how to record tens. Both are easy.
What is a complement? A complement is simply the digit that, added to the digit you have, adds up to ten. You might say that a complement is that digit needed (in addition to the one you have) to complete a ten.
For example: The complement of 9 is 1, because 9 + 1 is ten. The complementt of 8 is 2, because 8 + 2 is ten. The complement of 7 is 3, and the complement of 6 is 4, because 7 + 3 is ten and 6 + 4 is ten. Even in your sleep you would answer that the complement of 5 is 5.