Convert a fraction to a decimal number by dividing the the numerator (the top number) by the bottom number (denominator).
Add simple fractions (where the denominator is the same on each) together by adding the two numerators together, for example 1/4 plus 1/4 is 2/4 (1/2).
Subtract simple fractions by subtracting the two numerators from each other. For example 3/4 minus 1/4 is 2/4 (1/2).
Multiply fractions together by multiplying the numerators and then multiplying the denominators. For example 1/5 multiplied by 2/5 is 2/25.
Divide fractions by flipping the reciprocal and then multiplying the fractions together. For example to divide 2/3 by 1/4, flip 1/4 to become 4/1 and then multiply it by 2/3, which equals 6/3 (2).