She looked at me as if I were a small child. Then she said, very gently, “You know, it’s so much easier just to divide by seven,” Well this didn’t seem easier for me because, as I said, I found division to be more complicated than addition and subtraction. I thought her method was more difficult. But do you know what? I tried it a few times, and she was right. All you need to do is divide the total by seven, which gives you an estimate, and then you just add a little more. It is really quite easy.