Invisible Math

Math is invisible?  What does that mean?

Well, these parts of math aren’t really invisible, but we do have plenty of 1’s that like to hide and only pop out when needed.
For example:                        y = 1y                              or                        -m = -1m
Last week my student’s were combining like terms, so it was crucial that they recognized those invisible 1’s.
Here is a handout which I found from one of the Internet Math blogs