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.
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?
- Introduce the problem by displaying half past three on the clock and asking what programmes might be on TV at that time.
- Move the hands to 4 o'clock and ask what programmes would now be on.
- Pose the problem.
- Ask the students 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?
- Encourage the students to plan ways to keep track of their solution so that they can share it with others.
- 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?
This might be done with rods or by using a clock face. It might also be another chance to practice counting in 2s.
There are four hours to fill in. Each hour has two half-hour programmes. So PSTV needs 2 + 2 + 2 + 2 equals 8 programmes.