One owl has a wingspan of 1⁄2 foot. A second owl's wingspan is 3⁄4 foot. How much longer is the wingspan of the second owl?
Change 1/2 in fourths: 1/2 = 2/4.
Subtract: 3/4 - 2/4 = 1/4.
Since the denominators (bottom numbers) are the same, just subtract the numerators (top numbers) and write that answer above the common denominator.