New Zealand
Level 6 - NCEA Level 1

# Units of Time and Conversions

Lesson

We know that there are different measurements of time, such as seconds, minutes, hours and days. Some measurements of time are more appropriate for short periods of time, such as seconds or milliseconds. Some are more appropriates for long periods of time, such as years, centuries or even millenia!

In this chapter, we are going to look at how to convert between these different measurements.

Common Time Conversions

$\text{1 millenium}=\text{1000 years}$1 millenium=1000 years

$\text{1 century}=\text{100 years}$1 century=100 years

$\text{1 decade}=\text{10 years}$1 decade=10 years

$\text{1 year}=\text{365 days}$1 year=365 days

$\text{1 leap year}=\text{366 days}$1 leap year=366 days

$\text{1 year}=\text{12 months}$1 year=12 months

$\text{1 day}=\text{24 hours}$1 day=24 hours

$\text{1 hour}=\text{60 minutes}$1 hour=60 minutes

$\text{1 minute}=\text{60 seconds}$1 minute=60 seconds

$\text{1000 milliseconds}=\text{1 second}$1000 milliseconds=1 second

Converting time measurements is a bit like working with ratios that we have to keep in proportion. For example, we know that $1$1 minute is equivalent to $60$60 seconds.

From this, we can say that:

• $\text{2 minutes}=\text{120 seconds}$2 minutes=120 seconds (we have doubled both time measurements)
• $\text{3 minutes}=\text{180 seconds}$3 minutes=180 seconds (we tripled both of the original time measurements)

and so on.

Let's look at some more examples of converting measurements of time now.

#### Worked Examples

##### Question 1

How many minutes are in $12$12 hours?

##### Question 2

Convert $360$360 minutes into hours.

##### Question 3

If an average person showers for $6$6 minutes per day, how many hours do they spend in a shower in:

1. a year (assume non-leap year)?

2. $55$55 years (ignoring leap-years)?

### Outcomes

#### GM6-2

Apply the relationships between units in the metric system, including the units for measuring different attributes and derived measures

#### 91030

Apply measurement in solving problems