I’ve been doing homeschool math experiments all summer with my older son. I started division in April, when I realized it’s a third-grade topic that his third-grade classroom was not going to get to. At this point, we’ve been doing long division for six months and he still can’t do it.

I’ve sat next to him for every long division problem. We used Kumon, and School Zone and random downloads. Nothing works. Today I slammed my hand on the desk and said, “Focus on what you’re doing! You just did this yesterday!”

I broke a lot of blood vessels in my fingers. Not all of them, but just enough so that all day I have this bruised feeling on my hand.

This seems like a good time to tell you that my first job out of college was at the Chicago Mercantile Exchange. I was an arbitrage clerk and I used hand signals to tell traders on phones what prices were trading in the open-outcry pits. I did not get the job for any skill; traders in the pit wanted someone good to look at.

So I flashed numbers with my fingers for about three months, and then the Berlin Wall came down. The markets went up and down so fast and I couldn’t remember if numbers were higher or lower than previous numbers.

That day I was fired, and that day I realized that I had a disability. People who struck me as uneducated and stupid were able to keep track of what numbers meant in a market going up and down.

Today my son did the same long-division routine over and over again and he could not see he was learning a system to solve a problem. And everything came back to me. My own math gap, the Wall falling, and the teachers who told me I wasn’t trying my hardest and left me bruised.