Cool technique for multiplying squares

koconnor · 30-04-2007 8:57pm #1

Hey all,

Cool video on youtube to help calculate squares.

Click here

Get some paper and a pen and try them out!

I have more videos coming soon guys I hope you like them

Mellor · 30-04-2007 10:36pm

it doesn't work for numbers over 19,
most of these are going to be known without working them out,
12=144
13=169
.
.
19=361

is handy is you dont no them all or forget, but its fairly limited.

find be square roots and id be impressed, the pain of working backwards through floor areas.

JC 2K3 · 09-05-2007 1:27pm

It does work for numbers above 19....

20
20 + 10 = 30
30*10 = 300
10^2 = 100

300 + 100 = 400 = 20^2

The formula would be x^2 = (2x - 10)*10 + (x - 10)^2

The obvious flaw in this technique is that you're going to have to know what (x - 10)^2 is, which makes it rather pointless.

Fremen · 12-05-2007 2:34pm

One of the first things you learn in Junior cert. maths is

(x + Y)^2 = x^2 + 2xy + y^2

for say, 37, let x = 30, y = 7.
Then you can solve it easily in your head.

I'm not too keen on this vedic maths stuff, they don't normally explain the logic behind the techniques

Cool technique for multiplying squares

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