[discostu]

It teaches you that you can dissect numbers into easier to work with numbers to solve your problem. It’s kind of odd to do it with numbers that small and simple, but if you get good at it and keep in practice you can multiply 4 digit numbers in your head (or more really, I can do 4).

[Steve_Seattle]

"It teaches you that you can dissect numbers into easier to work with numbers to solve your problem."

It's a crappy way of doing it. What you propose is how algebra problems are solved, but they used to teach you the proper steps to do it. Now it seems like they want every third grader to somehow reinvent mathematics.