The main road in Belleville is 7 3/10 miles long.
so far 2 3/4 miles have been repaved. How many miles
have not been repaved?
7
= 7
= 6
-2 
= -2
= -2
———————————————————————
4
The first step was to get the least common denominator
of 10 and 4. Since 20 is the smallest positive integer
that both 10 and 4 will divide into evenly, 20 is the
LCD. So we changed the to and changed the
to . Then we noticed that the upper
fraction was smaller than the lower fraction
, so to make the upper fraction larger, we
borrowed 1 from the 7 leaving it as 6, then took the 1 that
we borrowed, thought of it mentally as 
and added it to the making it . Then
we merely subtracted the whole parts and the fraction parts.
Edwin
