Vote
80
up
9
down
report video
Math Trick Multiply Using Lines
Posted 10 years ago by sifter in category: interesting
Comments (1)
smithsc - 10 years ago [ Reply ]
0
up
0
down
It doesn't work if you make the groupings horizontally instead of vertically, or in quadrants instead of in one direction only. Seems to be somewhat coincidental to me.

 Reply to this post:
Add comment as a guest or [ login ] to use your username

Add comment as a guest or [ login ] to use your username