This free math tutoring video shows the first way to explain how to do mental subtraction. It is basically the opposite of the way of how mental addition is taught. The next video will show another way to teach subtraction, which may be easier for some problems. Both ways should be taught and children can choose which they like best.
Three manipulatives are shown as options for teaching this concept – plastic eggs, an abacus and Cuisenaire Rods. Feel free to substitute your own manipulatives. The important thing is that the children have something to TOUCH as well as look at when learning how to subtract this way. Enough times of doing it with manipulatives and they will begin to internalize the structure of the method and won’t need them anymore.
This free math tutoring video shows the first step in learning to do mental math. This teaching technique can be started as soon as children have their facts (number bonds) to 10 memorized. (VERY easy to do with Cuisenaire Rods! check out my other videos!)
Once children learn to add and subtract using “making tens” strategies for problems within 20, they can then take that knowledge and extend it to numbers within 100 and even within 1,000. I first learned this method from the Singapore Math curriculum. Too bad math isn’t taught this way in the U.S.
I’ve seen it with my own children. This concept is the key that opens the door…
