A unit fraction is a fraction where the top number, known as the numerator, is one, and the bottom number, known as the denominator, is any positive number. Additionally, the denominator must be an integer, or round number.
Unit fractions are the reciprocals of positive integers. For example, the reciprocal of two is the unit fraction one-half.
Unit fractions, when added, result in a fractional sum with a numerator that is the sum of the denominators of the factors and a denominator that is the product of the denominators of the factors. For example, the sum of one-third and one-fourth is seven-twelfths; the numerator is three plus four, while the denominator is three times four.