# 9.08 Timetables

Lesson

## Ideas

Can you  find the difference between two times  ?

### Examples

#### Example 1

Find the value of 5 hours 10 minutes - \, 2 hours 40 minutes.

Worked Solution
Create a strategy

Use a vertical algorithm and the conversion 1 \text{ hour}= 60 \text{ minutes}.

Apply the idea

To subtract the times, we can write it in a vertical algorithm. Make sure to align the hours, colon and minutes.\begin{array}{c} & &5 & : &10 \\ &- &2 & : & 40 \\ \hline & \\ \hline \end{array}

Since 10 minutes is less than 40 minutes, we trade 60 minutes from 5 hours.

So, we have 10+60=70 minutes in the first row and 5 hours becomes 4 hours.\begin{array}{c} & &4 & : &70 \\ &- &2 & : & 40 \\ \hline & \\ \hline \end{array}

Subtracting each column, we have:\begin{array}{c} & &4 & : &70 \\ &- &2 & : & 40 \\ \hline & &2&:&30 \\ \hline \end{array}

The difference is 2 hours and 30 minutes.

Idea summary

We can use subtraction to find the difference between times, but we have to be careful when we need to regroup and remember:

## Timetables

This video shows you some of the important things that you should consider when looking at public timetables.

### Examples

#### Example 2

If Charlie catches a train at 4:46 pm from Circular Quay, what time will he arrive at Central?

Worked Solution
Create a strategy

Search for the time in the Circular Quay row. Then go down the column to the Central row to find the train's arrival time.

Apply the idea

Charlie will arrive at Central at 4:55 pm.

Idea summary

Every timetable is different. Before you start answering questions on a timetable you haven't seen before, look at all the information, such as:

• what do the rows mean?

• what do the columns mean?

• are there abbreviations or symbols and do you know what they mean?

### Outcomes

#### MA3-13MG

uses 24-hour time and am and pm notation in real-life situations, and constructs timelines