Students learn that unit fractions are fractions with a one in the numerator, representing one part of the whole. All wholes can be broken up into unit fractions. For example 1/4 + 1/4 + 1/4 + 1/4 = 4/4 = 1
When adding and subtracting fractions, the denominators need to be the same. You add or subtract the numerators, while the denominator stays the same.
Students learn how to multiply a fraction by a whole number in three different ways. They first learn how to use a model, as pictured in the following two examples. They then learn how to use repeated addition to solve, as pictured first below. Finally, they learn how to solve using the formula, as pictured second below.