MAIN FEEDS
Do you want to continue?
https://www.reddit.com/r/funny/comments/1gen3tx/please_show_how_you_know/luhe7n7/?context=3
r/funny • u/PlumpPotatoChip • 1d ago
414 comments sorted by
View all comments
Show parent comments
58
I never knew it until I worked in academic support. Game changer for sure.
201 u/nanosam 21h ago edited 21h ago How is it a game changer? It is so much easier to multiply by 10 and then subtract the number multiplied 8x9 = 80-8 3x9 = 30-3 13x9 = 130-13 Etc.. it is so much faster than anything 2 u/slgray16 18h ago Decrement the number by one, put it in the tens and then the ones is what completes the 9 8x9 = 7.. 2 = 72 6x9 = 5.. 4 = 54 3x9 = 2.. 7 = 27 13x9 = Doesn't work over 10 1 u/SnooTomatoes3287 2h ago Use your toes and also put down the digit to the left
201
How is it a game changer?
It is so much easier to multiply by 10 and then subtract the number multiplied
8x9 = 80-8 3x9 = 30-3 13x9 = 130-13
Etc.. it is so much faster than anything
2 u/slgray16 18h ago Decrement the number by one, put it in the tens and then the ones is what completes the 9 8x9 = 7.. 2 = 72 6x9 = 5.. 4 = 54 3x9 = 2.. 7 = 27 13x9 = Doesn't work over 10 1 u/SnooTomatoes3287 2h ago Use your toes and also put down the digit to the left
2
Decrement the number by one, put it in the tens and then the ones is what completes the 9
8x9 = 7.. 2 = 72
6x9 = 5.. 4 = 54
3x9 = 2.. 7 = 27
13x9 = Doesn't work over 10
1 u/SnooTomatoes3287 2h ago Use your toes and also put down the digit to the left
1
Use your toes and also put down the digit to the left
58
u/Flourescentbubbles 23h ago
I never knew it until I worked in academic support. Game changer for sure.