There are many ways how to add or subtract fractions
Here i will show you one ways how to add them









4 2
_ + _
8 4

Step 1: you have to make the two bottom numbers the same so you have to find the common divisor.
How to find the common divisor? The common divisor is the number you can divide by 4 and 8.
Than you have to find out how often the number 4 and the number 8 fit in there.
In this case you have to make the number 4 into a 8. Than you have to times the top number by 2 because the 4 fits 2 times into the 8.
Than it looks like that


4 4

_ + _

8 8
Now you add the top numbers 4 and 4.







4+4 =8
so the answer is
8
_
8


and 8

8




How to subtract fractions



Subtract fractions and adding fractions are really similar!!



4 2
_ - _
8 4



Step 1 : The first step is the same step you have to make the 2 number on the bottom the same so you have to find the common divisor
How to fond the common divisor? the common divisor is the number you can divide the two number at the bottom. So you have to find a number that can get divide by 4 and 8 in this case it is 8 because 8 can get divide by 4 and 8.


4 4

_ - _

8 8
Now you add the top numbers 4 and 4.


But now it changes
unlike adding fractions where you just add the top numbers subtract everything.

So it is 4-4=0
and 8-8=0
The answer is 0