Multiplication by drawing lines

this is one of the coolest forwards that I received today. See how easy it is to multiply two numbers by drawng lines and intercepting the the intersection points.. Fundoo it is!

Category:

Howto & Style

Tags:

• maths
• trick
• multiplication

[hedong2009]

This is nothing new. I knew this method when I was Grade 3. Drawing lines is mimic the process of digits multiplying. This case is 21x13, in the form of Binomial theorem it is (20+1)x(10+3) which can be expanded as 20*10 + (20*3 + 10*1) + 1*3, in another form it is 2*100 + (6 + 1)*10 + 3 = 273. This is same process how the video shows adding each digit unit together. Drawing lines could be funny for kids who are trying to learn multiplying, however, it is useless while applying to big numbers.

[nevelis]

Yes it does.

[pinkbyfloyd]

it doesnt work for 21 x 27

[darito90]

works with any multiplicatoin

[fabicon]

Try 26*16

Then it wont work:S? or?