A fraction is a number that represents a whole number that has been divided into equal parts. A common, vulgar, or simple fraction consists of an integer numerator displayed above a line (or before a slash), and a non-zero integer denominator, displayed below (or after) that line. The numerator represents a number of equal parts; and the denominator, which cannot be zero, indicates how many of those parts make up a unit or a whole. Fractions can also be used to represent ratios and division.

Students may have difficulty in the following areas:

Believing that fractions’ numerators and denominators can be treated as separate
whole numbers.
• Failing to find a common denominator when adding or subtracting fractions with unlike
denominators.
• Believing that only whole numbers need to be manipulated in computations with
fractions greater than one.
• Leaving the denominator unchanged in fraction addition and multiplication problems.
• Failing to understand the invert-and-multiply procedure for solving fraction division
problems.
• Failing to understand reciprocal vs. invert-and-multiply procedures for solving fraction
problems.