Another video challenge to share, called Subtracting Reverses. Once again, a strange little mystery can motivate a ton of subtraction practice. The subtraction here is focused on 2-digit minus 2-digit examples. However, by coloring a hundred chart as you go, you can find really interesting patterns, many of which you may be able to explain.

If you want to take this problem to the next level, try reversing 3-digit numbers and see what happens when you take the difference!