How To Prove Anything Right?

Here's an interesting video that is taken from the movie, “In the Navy (1941)”. Watch the characters performed by Abbott and Costello proving 7 x 13 = 28!

We can use this film for various purposes.
If you're a HR person, you may want to show that there are many ways to find an answer and that not all answers are right, but the thought process tells us that we think and that is more important!
You can also use it to show you can prove anything right, if you work at it.

Math teachers can use this as an example for teaching place value.