Adding Odds and Evens

The significance of understanding whether an answer is going to be odd or even is not often instantly understood. If children understand this, they will have an instant way to know whether their answer may be wrong. They will know that 459+243 has to be even because they are both odd numbers. It develops numbers sense. That’s a good thing!

After watching this free math video, I see how I could have done things a little better. Writing all even numbers in red and odd numbers in black would have helped tie in the Cuisenaire Rods to the symbols. Our numerals themselves show no similarity to quantities (what does the shape of a 5 have to do with five things?) so bridging that gap with colors or letters to indicate odd or even would be a good idea.

Adding Decimal Fractions

Once children have had extensive practice using Cuisenaire Rods to work with fraction concepts, they are ready to move on to decimal fractions. In this free math video, my daughter transfers her knowledge of adding fractions using the rods to adding decimal fractions written in decimal notation. At this point, I still have not told her any of the rules for fractions or decimals. I am letting her come to that understanding on her own. Watch carefully in these videos and you’ll see her making connections on her own.

Adding and Subtracting Fractions with Different Denominators

This free math video was kind of an experiment to see if my 8-year-old could assimilate all the information she’d learned thus far about fractions into adding and subtracting fractions with unlike denominators. I DO NOT want to give her rules until she has internalized the concepts, and, actually, I would prefer that she come up with the rules on her own when at all possible. That is why you will not see me straight up telling her what steps to take. I ask her what she thinks she should do, I give her a hint or the first step, but I try hard not to jump ahead to a “formula” too quickly. Understanding math concepts means understanding for life. Memorizing algorithms means forgetting in 10 or 20 or 30 years and feeling dumb. I’d prefer my children to actually understand this stuff!

Adding and subtracting fractions with Cuisenaire Rods looks exactly the same as adding whole numbers with the rods. The difference is in what rod you are calling “one.” Knowing how to add, subtract, multiply and divide whole numbers with the Cuisenaire rods makes it easy for her to do the same with fractions.