Erin is going to sew a jacket and a skirt. She needs 2 3/4 yards of material for the jacket and 1 1/2 yards of material for the skirt. Altogether, how many yards of material does Erin need?

You add the fractions.

turn it into an improper fraction. you multiply the whole number by the denominator then add the numerator, leaving it over the original denominator.

eg / 2*4 = 8 + 3 = 11/4

1*2 = 2 + 1 = 3/4

find a common denominator.

eg / 2 and 4 have the common denominator of 4.

then you make the denominators the same.

eg / 3/2 * 2 = 6/4

add them.

eg / 11/4 + 6/4 = 17/4

lowest terms.

eg / 4 1/4