Comment on 10!=10*9*8*7*6*5*4*3*2*1
NeatNit@discuss.tchncs.de 2 days ago
Fine, I’ll do the math:
60 seconds in a minute (10 × 6)
60 minutes in an hour (9 × 5 × 4 / 3)
24 hours in a day (8 × 3)
7 days in a week (7)
6 weeks (3 × 2)
The bold 3’s cancel out and become × 1, and then it’s easy to see each integer from 1 to 10 appears exactly once when it’s all multiplied together.
Xavienth@lemmygrad.ml 2 days ago
Much easier to start if you know there are 3600 seconds in an hour. 36 is 9×4 and 100 is 10×5×2. Then 24 hours is 8×3, and 6 weeks gives you 6×7 (hand gesture).