7/10 - 1/2......to add/subtract fractions u need a common denominator. The lowest common denominator for 10 and 2 is 10. So we change each fraction to make it have a denominator of 10.
7/10 does not have to be changed because it already has a denominator of 10.
1/2 = 5/10
now we have :
7/10 - 5/10.....now we subtract = 2/10 which reduces to 1/5
