Begin with



then write the  as 



Now we know that , so we make a
unit fraction (one that equals 1) from that. We
will put the  in the denominator so
it will cancel with the  in the numerator.
So we will multiply by 

×

and, as you see, the grams 's cancel out:

×

Now we know that , so we make a
unit fraction (one that equals 1) from that. We
will put the  in the numerator so
it will cancel with the  in the denominator.
So we will multiply by .
However since there are three factors of ,
we will multiply it three times:

××××

Now you see that the 's all cancel out

××××













Edwin