Fractions represent parts of a whole. They are written with a numerator above a denominator. Fractions can be added, subtracted, multiplied and divided. Equivalent fractions have the same value even if their numerators and denominators are different. Mixed numbers contain both a whole number and fractional parts, while improper fractions have numerators larger than the denominators. Fractions can be changed between mixed and improper forms and placed on a number line to compare sizes.