Reciprocals and Dividing by Fractions
Summary of the Math: Reciprocals and Dividing by Fractions
Read and Discuss
- The fractions and , with numerators and denominators inverted, are called reciprocals of each other.
The key property of reciprocals is that their product is always 1.
Reciprocals are also called multiplicative inverses. This name refers to the fact that if you multiply a fraction by a number, and then multiply the result by the reciprocal of the fraction, the result is “undone.” For example:
- You can use the properties of reciprocals to help you divide by fractions. The general rule is: To divide by a fraction, multiply by the reciprocal of the fraction. Algebraically, the rule looks like this:
- Solve a problem that involves dividing a fraction by a fraction?
- Determine which operation is needed to solve a word problem?
- Explain what reciprocals are and how to use them to help you solve division problems involving fractions?