# The Z Factor

Pupils determine how long it would take a panel of judges if they saw every act that auditioned for the “Z factor” programme.

# Practical details

Suitability
National Curriculum levels 3 to 8
Time
45 minutes to 1 hour
Resources
Paper and calculator

# Key Processes involved

Representing
Simplify the problem by making appropriate assumptions
Analysing
Combine assumptions and work logically to solve the problem
Communicating and reflecting
Throughout, present arguments and reflect on findings, recognising the impossibility of the scenario presented

# Teacher guidance

You could start by showing pupils relevant pictures or videos from http://xfactor.itv.com/

• For the TV programme, there are thousands of people wanting to audition. How do they decide which acts get through this first set of auditions?
• To answer the question, you will need information that is not given, so you will have to make assumptions (sensible guesses) – and explain them.

The task requires multiplicative calculations involving time.

The following probing questions may be helpful:

• What do you need to know? As you work through the problem, write down the questions for which you need answers
• Make sensible guesses for the answers; what assumptions are you making? Why?
• Have you decided to ignore any factors? Why?
• What does your solution tell you about the auditions for the Z Factor?

Two key assumptions are needed: 1) How long an audition lasts; 2) The number of hours in a judges’ working week. Pupils’ assumptions should be vaguely realistic! Pupils might work backwards, assuming all auditions are seen and finding how long each one would need to be; this does not answer the question asked, but it does show insight into the situation and the mathematics is equally complex.