Lesson 4: Time: Conversions & Operations

Property

The standard units of time are related by factors of 60.

• $1 \text{ hour} = 60 \text{ minutes}$
• $1 \text{ minute} = 60 \text{ seconds}$

Examples

• To convert 4 hours to minutes, you multiply by 60: $4 \text{ hours} \times 60 = 240 \text{ minutes}$.
• To convert 180 seconds to minutes, you divide by 60: $180 \text{ seconds} \div 60 = 3 \text{ minutes}$.
• To convert 2.5 minutes to seconds, you multiply by 60: $2.5 \text{ minutes} \times 60 = 150 \text{ seconds}$.

Explanation

This skill covers the basic conversions between hours, minutes, and seconds. To convert a larger unit of time (like hours) to a smaller unit (like minutes), you multiply by 60. To convert a smaller unit (like seconds) to a larger unit (like minutes), you divide by 60. Mastering these conversions is a key first step for solving multi-step problems involving time.

Property

To solve time word problems, a common strategy is to convert all given times into the same, smaller unit. For example, convert all hours and minutes into just minutes. After converting, perform the required arithmetic operations like addition or subtraction.

Examples

A movie lasts 2 hours and 15 minutes. How long is the movie in minutes?

• First, convert hours to minutes: