"until probably 100 or 144" - ugh. That's 10 and 12. I hope he 's wrong about that and schools aren't that bad where he lives. In Germany we've had to memorize squares for numbers 1 to 20 and 25, which gives you the roots of 1, 4, ..., 100, 121, ..., 400, 625. For every other number beetween these, you can estimate the root with two decimal places pretty well.
I fail to see a correlation between how good a school is and how many squares of numbers you have to memorize. I don't remember being forced to memorize any higher than 10 at either of the schools I went to and I'd classify them both as 'good' in the grand scheme of things. Once you know the multiplication table up to 10 and a couple of techniques for multiplying larger numbers there really is no need for memorization.
Ha ha, yes, how bad those schools must be. They are wholly dependent upon Germans to answer the tough questions, like what is the square of 25, and what's your best guess for the square root of 21.
One only needs to remember a simple algorithm to compute any square by hand, and realistically a computer is always a better choice. I can't understand why you think memorizing more squares provides a better math education.
He's not wrong, though I think most people know 25^2
in general schools only teach 1-12.
My mother was/is kinda a math freak (in a good way) and made sure that we knew our squares through 20 plus fun numbers like 25(625) and 45 (2025) among other things (like decimal division).
She'd always decry our meager American education compared to her Soviet one, fun times.
