I’m not sure who decided that Ann Arbor Public elementary schools should teach children Everyday Math, but I hate it.

Recently, I discovered the frozen-over hell that is partial sums. For those who didn’t learn math this way, partial sums ultimately boils down to performing single digit addition from left to right. Which means anytime a number not in the highest number value place exceeds 10, things have to be corrected. For example, if you take the problem 549 + 327, under partial math, your thinking strategy works something like this:

In other words, partial sums boils down to performing the problem backwards, since at the end of the day, you’re doing addition at the single digit level, which also means you have to continually correct your math if you run into a “carry-the-one” situation. It gives the child more opportunities to mess up, since they have to keep going back and correcting the numbers they had already calculated, which were calculated correctly, but actually need to be increased because of high numbers in lesser place values. How is this easier/better than the traditional carry-the-one method?

My understanding is that this practice is intended to teach children place values. But that seems like place value could easily be taught via expanded notation, while still solving from right to left so you don’t have to repeatedly “correct” your math:

… see why I hate this shit?