# Converting units of time review (seconds, minutes, & hours)

CCSS Math: 5.MD.A.1
Review the size of seconds, minutes, and hours and how to convert between them.  Then, try some practice problems.

### Units of time

Units of time measure how long something lasts. For example, how many seconds can you hold your breath, or how many minutes long is your favorite movie?

## How long are different units?

A second is a short amount of time. It takes about $1$ second to turn on a light or open the refrigerator door.
A minute is equal to $60$ seconds. It takes about $1$ minute to brush your teeth.
An hour is equal to $60$ minutes. Extracurricular activities (gymnastics, piano lessons, soccer practice) often last about $1$ hour.

## Practice set 1: Estimating time

Problem 1A
Identify the most reasonable unit to measure the time it takes to bake a pan of cookies.
Want to try more problems like this? Check out this exercise.

## Converting larger units to smaller units

$1 \text{ minute} = \greenD{60}\text{ seconds}$
$1 \text{ hour} = \greenD{60}\text{ minutes}$
To convert larger units to smaller units we multiply the number of larger units by $\greenD{60}$.
Example: Converting hours to minutes
$1 \text{ hour} = \greenD{60}\text{ minutes}$
$\blueD{6} \text{ hours} = \blueD{6}\times \greenD{60}=360\text{ minutes}$

## Converting smaller units to larger units

To convert smaller units to larger units we divide the number of smaller units by $\greenD{60}$.
$1\text{ second}= \dfrac1{\green{60}} \text{ minute}$
$1\text{ minute}= \dfrac1{\green{60}} \text{ hour}$
Example: Converting seconds to minutes
$1\text{ second}= \dfrac1{\green{60}} \text{ minute}$
$\pink{30} \text{ seconds}= \dfrac{\pink{30}}{\green{60}}=\blue{\dfrac1{2}}\text{ minute}$
$11$ minutes $=$