This video tutorial is in the Education category which will show you how to subtract basic fractions in simple mathematics. You can do basic subtraction of fractions if the denominators are the same. If they are not, then find the lowest common multiple of the denominators and convert the denominators to their lowest common multiple. For example, to subtract 1/2 from 3/4 find the common multiple of 2 and 4, which is 4. So, the problem 3/4 - 1/2 can now be written as 3/4 - 2/4. Since, the denominator is multiplied by 2, the numerator also has to be multiplied by 2. The answer is Â¼. That's it!