Hippo Hopping is a cartoon-based visual way of solving expanding an expression using the distributive property.
I developed the term back when my daughter thought that she hated math. I tried to make every math lesson into a cartoon and a fun activity. I guess this is what ultimately led to the Doodles Do Algebra math curriculum, but it really worked for my kids and so that is how we ended up there.
My daughter was learning the distributive property. She was quite young for the complexity of the math she was learning, but the math wasn’t really the problem. It was some of the terms. They were too boring and abstract for her. And given other learning challenges she was fighting at the time, we generally ended math lessons with my daughter in tears.
I needed an outrageous name that would interest her – and so ‘hippo hopping’ was born.
Let’s take 3(a+b) as an example and watch the hippos hop.
The way it works is the hippo stands on top of the number that will do the hopping, in this case the 3, grabs it in its jaws and hops (using its immense belly as a ‘hippity-hop’ bouncing ball) first to the a (the first term). When the hippo lands on the a, the 3 replicates and multiplies the a to make 3a. Then, job done, the hippo bounces back to its starting point on top of the 3, picks up the 3 in its jaws and hops over to the b, multiplying the two together and getting 3b. So once the hippo is finished 3(a+b) becomes 3a +3b.
Now hippo hopping may not suit you and your family, so if it is not something that excites the imagination of your child – or if you dread the day your son gets into his first engineering course at MIT and tells his professor that he solved the equation using ‘hippo hopping’, then just ignore all future references to hippo hopping.
But if you think your child might understand the distributive property a bit better this way, then use ‘hippo hopping’ freely and without reservation.