Do the Math...Or Not

Oldie had decided that they could, with less trouble to himself, be made to do arithmetic. Accordingly, when you entered school at nine o'clock you took up your slate and began doing sums. Presently you were called up to "say a lesson." When that was finished you went back to your place and did more sums - and so on forever. All the other arts and sciences thus appeared as islands (mostly rocky and dangerous islands) [...] --the deep being a shoreless ocean of arithmetic. At the end of the morning you had to say how many sums you had done and it was not quite safe to lie. But supervision was slack and very little assistance was given. My brother [...] soon found the proper solution. He announced every morning with perfect truth that he had done five sums; he did not add that they were the same five every day.
~C.S. Lewis, Surprised by Joy, "Concentration Camp", 1955

I could never have gone far in any science because on the path of every science the lion Mathematics lies in wait for you. Even in Mathematics, whatever could have been done by mere reasoning (as in simple geometry) I did with delight; but the moment calculation came in I was helpless. I grasped the principles but my answers were always wrong. Yet though I could never have been a scientist, I had scientific as well as imaginative impulses, and I loved ratiocination.
~C.S. Lewis, Surprised by Joy, "The Great Knock", 1955

I am also bad at Maths and it is a continual nuisance to me - I get muddled over my change in shops. I hope you'll have better luck and get over the difficulty! It makes life a lot easier.
~C.S. Lewis, Letters to Children, (1985)