Fraction rules
a/b + c/d = (a×d + c×b) ÷ (b×d)
a/b − c/d = (a×d − c×b) ÷ (b×d)
a/b × c/d = (a×c) ÷ (b×d)
a/b ÷ c/d = (a×d) ÷ (b×c)
Then simplify by dividing the top and bottom by their greatest common divisor.
Example
3/4 + 2/3: the common denominator is 12, so it’s 9/12 + 8/12 = 17/12, which is 1 5/12 as a mixed number, or about 1.4167.