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Cross-curricular — maths

Nikau frond leaves woven into a natural pattern.
Continue your students' social inquiry with these maths activities that explore the gender pay gap.

Statistical processes

At level 5, the gender pay gap is a useful context for exploring the following statistical processes:

  • evaluating statistical investigations undertaken by others, including data collection methods, choice of measures, and validity of findings
  • comparing sample distributions visually using measures of centre, spread, and proportion.

Background information

Stats NZ provides useful information on measuring the gender pay gap, which explores 4 questions:

  • What is the gender pay gap?
  • How does Stats NZ measure pay?
  • Which measure does Stats NZ recommend?
  • What does the gender pay gap look like in New Zealand?

They also provide information about how the pay gap has changed over time.

Organisational gender pay gaps: Measurement and analysis guidelines

Gender pay gap is second-smallest

Introducing the topic

Watch videos related to equal pay campaigns, for example:

Treat Her Right, 2017 (YouTube, 0:58)


Measures of central tendency

This activity helps students understand means and medians.

  • Explain how the gender pay gap is calculated (percentage difference between male and female rates of pay).
  • Discuss why Stats NZ uses median income rather than mean income when comparing the rates of pay of women and men in New Zealand.
  • Discuss why Stats NZ uses hourly pay rather than weekly or annual income to compare the amount of money women and men earn.
  • Discuss why Stats NZ includes the hourly rates of part-time workers when calculating the gender pay gap. Note that about 1 in 3 women work part-time compared to around 1 in 10 men. Part-time work tends to be lower paid than full-time work. For example, there are not many part-time CEOs, but people who work as caregivers, cleaners, or labourers are often employed on a part-time or temporary basis.

Displaying data

Have students create visual displays of changes in the gender pay gap over time using data available on the Ministry for Women website.

Get data from the Ministry for Women

Have them write statements that show what stories the graph shows.

Analysing box plots

The State Services Commission (SSC) webpage provides a number of box plots that students can analyse.

Get information from the SSC

The graphs are useful for broadening discussions about gender pay beyond just median rates of pay. For example, in almost all categories of profession in the survey, the highest paid males earned more than the highest paid females. The gap is the most evident in highly paid professions such as managerial, legal, human resources, and finance professions.