Proving Negative Times Negative Equals Positive With Blocks

There was a time when learning math was an exercise in tediousness. Thankfully, there are educators who come up with the most fun and creative ways to teach and illustrate mathematics. So how about the following video in which we get a visual demonstration why negative times negative must be positive.

Learning that negative times negative equals positive the fun way

Take Mike Lawler, for example. With his TwitterMath series on his YouTube Channel, he demonstrates certain math principles in a very entertaining way. In this case, he shows kids that a negative times negative is a positive. The fun part comes in when he makes use of colorful blocks to illustrate the principle and once again answer the question, “why is negative times negative positive?”.

For many of us, the principle of multiplying negative times negative yielding a positive has been learned practically eons ago. Lawler’s video, however, proves to us yet again the validity of the principle, and in a very fun way no less.

Math Principles Proven Again and Again

This only goes to show that any given mathematical principle can be proven over and over again in other contexts. Many of us are visual learners – especially younger children. So seeing (-2) x (-2) expressed with (missing) building blocks is a winner, especially when that principle is re-proven again and again as they grow up.

One thing worth noting is the fact that in this video, Lawler has in effect connected the negative times negative equals positive principle with the distributive property, which is yet another principle of mathematics. This just shows how good a teacher he is, and it is something that most math teachers should incorporate into their teaching: the ability to make students see an entirely different picture by connecting something they already know with things that they have yet to learn.

Watch the video below and see how it’s done.

Do you have any favorite examples of how people have illustrated negative number multiplication?

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