When do you add fractions when baking?

Answer 1

In order to add fractions, they must have the same denominators. If the fractions you wish to add do not already have the same denominators, they can be made to do so by finding the right number by which to multiply both the numerator and the denominator of each fraction. To find this number, multiply all the distinct denominators together, then multiply both the numerator and denominator of each fraction by a number found by the dividing the product of the distinct denominators by the denominator of the particular fraction concerned. All the fractions will then have the same denominator. Add the numerators of such fractions together to find the numerator of the sum; its denominator will be the one common to all the fractions.