# 3.2 Area and Multiplication

## Unit Goals

• Students learn about area concepts and relate area to multiplication and to addition.

### Section A Goals

• Describe area as the number of unit squares that cover a plane figure without gaps and overlaps.
• Measure the area of rectangles by counting unit squares.

### Section B Goals

• Explain why the area of a rectangle can be determined by multiplying the side lengths.
• Solve problems involving the area of rectangles.

### Section C Goals

• Find the area of figures composed of rectangles.

### Glossary Entries

• area

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

• array

An arrangement of objects in rows and columns. Each column must contain the same number of objects as the other columns, and each row must have the same number of objects as the other rows.

• bar graph
A way to show how many in each group or category using the length of rectangles.

• equation

A statement that includes an equal sign (=). It tells us that what is on one side of the sign is equal to what is on the other side.

• expression

An expression has at least 2 numbers and at least one math operation (such as addition, subtraction, multiplication and division).

• factor
When we multiply two whole numbers to get a product, each of those numbers is a factor of the product.

• key
The part of a picture graph that tells what each picture represents.

• multiplication
The operation that tells you the total number of objects when you have a certain number of equal groups.

• parentheses
Grouping symbols that can be used in expressions or equations, such as: $$(3 \times 5) + (2 \times 5), (24 \div 2) + 5 = 17$$.

• picture graph
A way to show how many in each group or category using pictures of the objects or symbols.

• product
The result of multiplying some numbers.

• scaled bar graph
A bar graph marked in multiples of some number other than 1.

• scaled picture graph
A picture graph where each picture represents an amount other than 1.

• square centimeter

A square with side lengths of 1 centimeter.

• square foot

A square with side lengths of 1 foot.

• square inch
A square with side lengths of 1 inch.

• square meter
A square with side lengths of 1 meter.