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.
I apologize for the chaotic nature of this free math video. I should have sent them out to run around first, apparently! Try to ignore all the random noises and I’m sure you’ll get something out of this!
This is just a brief introduction to the idea of “completing the square.” We will add more to this eventually, but I just want them to get the idea of dividing the coefficient of “x” in half and then squaring that number to complete the square. Obviously they need a few more times of this for it to really sink in!
Once you’ve gotten used to using the blocks, it becomes quicker to just draw pictures… and once you’ve drawn pictures enough, it becomes easier to just use symbols! The concrete-pictorial-abstract order of teaching has been proven to be the most effective. Here’s how you can do it with algebra concepts…