Convert to improper fraction (multiply whole number by denominator and add numerator, keep the denominator)
5 1/4 = 21/4
4 1/2 = 9/2
Multiply 9/2 by 2/2 to get the same denominator = 18/4
Subtract the numerators, keep the denominator.
21/4-18/4 = 3/4.
