HAVE A BREAK
At break time at school or in the office try out this elegant way of multiplying numbers using a simple pattern.
- 21 x 23 = 483
This is normally called long multiplication but
actually the answer can be written straight down
using the VERTICALLY AND CROSSWISE
We first put, or imagine, 23 below 21
There are 3 steps:
a) Multiply vertically on the left: 2 x 2 = 4
This gives the first figure of the answer.
b) Multiply crosswise and add: 2 x 3 + 1 x 2 = 8
This gives the middle figure.
c) Multiply vertically on the right: 1 x 3 = 3
This gives the last figure of the answer.
And thats all there is to it.
- Similarly 61 x 31 = 1891
- 6 x 3 = 18; 6 x 1 + 1 x 3 = 9; 1 x 1 = 1
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Have A Break
resides in mathematics