How do you simplify # 1/5 + 3/5#?

1 Answer
Sep 4, 2016




The top number of a fraction (numerator) is the count.

The bottom number (denominator) is the size indicator of what you are counting. In this case the size indicator is 5 which means it takes 5 of what you are counting to make a complete 1 of something.

As the 'size indicators' (denominators) are the same we can directly add the counts (numerators).

Write as:

#(1+3)/5 = 4/5#

#color(blue)("Tip about notation")#

Suppose we had: #3/10+2/10+16/10#

What we a counting is all of size type 10 (have the same denominator of 10)

As they are all of the same size it is perfectly correct to write it as:

#("count")/("size indicator")" "->" "(3+2+16)/10" " ->" "("numerator")/("denominator")#

This simply means that every one of what we are counting is size type 10. If you like: they are sharing the one size indicator notation(denominator of 10).