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.