Japanese multiplication [how it works: [📹 mathswithmisschang:

5 seconds

Informative but 21 * 42 = (840+42) = 882

😂😂😂😂 This is also a part of Vedic Mathematics not Japanese

Cool, but it's easier for me to multiply it the usual way. :)

Neat trick but this doesn’t build numeric intuition

No Japanese people do this. Additionally, it unnecessarily complicates the calculation when a product of two single-digit numbers exceeds ten. When 9 x 9 appears somewhere, do you really count 81 dots?

@trolland4 Algorithm works but it’s only elegant with those 2 digits numbers

Every person on this website just focuses on belittling others and exposing the negatives in everything while completely ignoring the beauty.

Taking too much space on the sheet and time. Totally unnecessary.

Pretty sure my weak at math brain does it quicker than 23 seconds.