What is the sum of 4/10 and 40/100?

First, make the denominators the same.

10 x 10 = 100
4 x 10 = 40
So 40/100 + 40/100 = 80/100. All you need to do is simplify.

So the answer id 80/100 or if you need it to be reduced it would be 4/5, you are probably wondering how i  did that so here is how
4/10 +40/100    
you can't add those because they do not have  the same denominator so we would have to change that to 100, 4x10=40 and 10x10=100
which gives you 40/100
then you add 40/100 + 40/100 = 80/100
now if you have to reduce that you divide the answer by 20 both denominator and numerator. That is what gives you 4/5