Factoring non-monic quadratics using algebra tiles

Students will learn how to factor non-monic quadratics using algebra tiles. Because they already know how to factor monic quadratics using algebra tiles, this skill should be easy to learn. We teach it because it's a good segue to the box method, which is itself a segue to the abstract method.

Concude by giving your students this challenge:

I can reverse 12 by adding 9 to it: 12 + 9 = 21.
I can reverse 15 by adding 36 to it: 15 + 36 = 51.
What must I add to 141414 to reverse it?

Here's the solution.

Note: I rewrote the problem because I thought its presentation was hokey.