Problem
PSTV is planning to show wildlife films in the time slot between 1 o'clock and 5 o'clock on Thursdays. If each programme lasts half an hour, how many different programmes will they need to buy to fill the time slot?

What is this problem about?
This problem helps explore the idea of half-hours. This is both an important concept in time and a useful application of the simple fraction one-half.

Achievement Objectives
Measurement (Level 1)
- read aspects of time, including clocks (to hours and half hours).

Mathematical Processes
- devise and use problem solving strategies to explore situations mathematically;
- use equipment appropriately.

Resources
Clock
Blackline master of the problem (English)

Specific learning outcomes
The children will be able to:
- read time in half-hours
- state that there are 2 half-hours in an hour
- count in 2s to 8.

1. Introduce the problem by displaying half past three on the clack and asking what programmes might be on TV at that time.
2. Move the hands to 4 o'clock and ask what programmes would now be on.
3. Pose the problem.
4. Ask the children questions that focus their thinking on telling the time in ½ hours.
   What time is this?
   How do you know?
   Tell me what the time would be in half an hour from then?
   Can you show me that time on the clock?
5. Encourage the children to plan ways to keep track of their solution so that they can share it with others.
6. Share solutions.

Extension to the problem
How many programmes would PSTV need from 11 o'clock in the morning until 6 o'clock in the evening?