# 5.3 Multiplying and Dividing Fractions

## Unit Goals

• Students extend multiplication and division of whole numbers to multiply fractions by fractions and divide a whole number and a unit fraction.

### Section A Goals

• Recognize that $\frac{a}{b} \times \frac{c}{d}=\frac{a \ \times \ c}{b \ \times \ d}$ and use this generalization to multiply fractions numerically.
• Represent and describe multiplication of a fraction by a fraction using area concepts.

### Section B Goals

• Divide a unit fraction by a whole number using whole-number division concepts.
• Divide a whole number by a unit fraction using whole-number division concepts.

### Section C Goals

• Solve problems involving fraction multiplication and division.

### Glossary Entries

• area

The number of square units that cover a flat figure without gaps or overlaps.

• cubic unit
A unit cube with side lengths that are standard measurement units that is used to measure volume.

• rectangular prism
A solid figure which has six faces that are rectangles.

• unit cube
A cube whose sides are 1 unit long, used to measure volume.

• volume
The number of unit cubes that fill a solid figure without gaps or overlap.