User contributions
- 11:19, 29 July 2020 (diff | hist) . . (-375) . . Simon's Favorite Factoring Trick (→The General Statement)
- 15:57, 5 June 2020 (diff | hist) . . (+785) . . N How many times does the digit 9 appear in the list of all integers from 1 to 500? (The number $ 99 $, for example, is counted twice, because $9$ appears two times in it.) (The answer is... 100)
