It was on 6 x 9 that I snapped. We had been over it dozens, maybe hundreds, of times. “52?” she’d say. “No, 56!” I could swear she’d had her math facts down cold by the end of 3rd grade, but here we were, six weeks into fourth grade, and she was still guessing. That’s when I uttered one of those lines that I began to regret even as I heard it leave my lips: “You’ll never get to the fifth grade if you can’t learn these multiplication tables!” I shouted. Her little freckled face crumpled. “You’re going to have to get a tutor!” I added for good measure. Now in some houses, a tutor would be considered a birthday present–or at least a routine event, like gymnastics–but in mine it ranks well below a flu shot. (It takes longer.) “Not a tutor!” she wailed.

She stomped off in a hail of tears, leaving me to ponder once again: what is wrong with me? Why do I regularly say to my children the exact opposite of what I know I should say? I am perfectly kind and encouraging to my students, and to the children of friends. But somehow when I’m talking to my own kids, a filter comes off that would no doubt be better left in place.

To be sure, I am especially leery of mathematical ineptitude; my own skills peaked with long division in fourth grade, and have been on a precipitous decline ever since. The multiplication tables are, in fact, among the very few things I still remember. How could she not know that 6 x 9 is 54?

But the truth is, I have said many ugly, inappropriate and/or irrational things to my children over the years that are not related to math, including “Get your own goddamned milk!” (to a whiny toddler) and “You’re acting like kind of an asshole!” (to a moody teen). At various times, I have looked one or more of them in the eye and accused them of being spoiled, selfish, bratty, obnoxious or annoying. “And you’ve called me a bitch!” my 16-year-old daughter reminded me cheerfully when I sought help remembering all my terms of endearment. At least once I said, “I could just kill you!” though now I can’t remember why. I’m sure it involved AirSoft pellets or possibly a tie-dye kit.

If I overheard a stranger say any of these things, I’d condemn her as a cruel, unfit mother bent on creating miserable children with flagging self-esteem. But of course, that’s not me! Indeed, I have managed to convince myself that my harsh tongue serves an important evolutionary function: it makes my children tougher and more resilient, teaches them that they are not the precious, infallible center of any universe, and allows them to see their mother as a flawed human being who loves them but sometimes shoots off her mouth unnecessarily. Not least, I hope it also helps them understand that sometimes they really do act like jerks. But not because they can’t multiply.