Problems for Children from 5 to 15

V.I. Arnold "Problems for children from 5 to 15" [0]. The book was discussed on HN in 2021 [1] (325 comments) If you have kinds and teach them math this book has mind-opening problems that even curious adults would enjoy. [0] https://www.imaginary.org/sites/default/files/taskbook_arnol... (https://www.imaginary.org/sites/default/files/taskbook_arnold_en_0.pdf) [1] https://news.ycombinator.com/item?id=27884973