Lesson 4: Multiplication and Division Word Problems

New Concept

This course teaches you to translate word problems into mathematical formulas. We begin with a key pattern for many problems: the 'equal groups' relationship.

What’s next

Soon, you will master the 'equal groups' formula through clear examples. We'll then apply it to word problems involving multiplication and division.

Property

To solve word problems with equal groups, use the formula:
number of groups $\times$ number in group = total

Examples

• Carver saw 30 rows of tiles with 32 tiles in each row: $30 \times 32 = 960$ total tiles.
• Olga bought five cartons of one dozen eggs each: $5 \times 12 = 60$ total eggs.

Explanation

Think of this as a magic recipe for word problems! If you know the number of groups and the amount in each group, you just multiply them together to find the grand total. It organizes everything neatly so you know exactly what to do, whether you're multiplying or dividing.

Property

If a factor is missing in the equation $n \times g = t$, you find it by dividing the total by the known factor.

Examples

• 360 chairs total with 15 in each row: $n \times 15 = 360 \rightarrow n = 360 \div 15 = 24$ rows.
• 98 band members in 14 equal rows: $14 \times g = 98 \rightarrow g = 98 \div 14 = 7$ members per row.

Explanation

Think of it as working backward! When you already have the total and know the size of each group, division is your trusty tool to figure out exactly how many groups there are. It’s like unscrambling a multiplication problem to find the missing piece of the puzzle.