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[music introduction]
[feet shuffle, coughing]
A multiplication table is useful for many, many things
A nice trick is to use the table to find equivalent fractions
here's how it's done
First of all
we select rows for the numerator and the denominator
In this case
row three is the numerator
and row four is the denominator
by selecting different columns
we can determine different equivalent fractions
as you can see
three fourths is equal to six eighths
which is equal to nine twelfths
and so on across the columns
also
you don't have to pick rows next to each other
in order for this to work
For example
select row five as the numerator
and row nine as the denominator
You'll see as you move across the columns
the resulting equivalent fractions
five ninths is equal to ten eighteenths and fifteen twenty-sevenths
and so on across the columns
but none of this means much without knowing why it works this way
the reason is mighty simple
both the numerator and the denominator of the fraction
are located in the very same column
this means they are both multiplied by the same number
for example
let's look at four sevenths
an equivalent fraction would be twenty-four forty-seconds
that's because both twenty-four and forty-two are in the same column
since the numerator four
and the denominator seven
are both multiplied by six
to get twenty-four forty-seconds
that's the same as multiplying by the equivalent of one
So remember
if you've got a multiplication table
you've got one mighty powerful tool
Uh-oh
well
it looks like I'm about out of ti