Half Squares
Pretty tricks for
doing mental arithmetic are often useful. Here is one that is particularly nice.
The Problems:
You probably know
that 5 x 6 = 30…
Now calculate 5.5 x 5.5
( or 5.52 ) on a calculator.
Can you see the connection?
Try 2.52
(close to 2 x
3),
7.52 and
19.52
as well, to check your
method.
Can you see how the
diagram below explains why the method works ?
Can you now see how to
simply write down:
252
, 752
and 1952
as well?
Open the File as a Word Document