Year level: 10

Strand: Measurement / Statistics

Lesson length: 60 mins

This lesson introduces students to the idea of a log scale, a seemingly perplexing way to present data. The lesson begins with an exploration of examples when a linear scale is inappropriate and concludes with a plotting activity using authentic data from the COVID-19 pandemic.

### Achievement standard

Students interpret and use logarithmic scales representing small or large quantities or change in applied contexts. They analyse inferences and conclusions in the media, noting potential sources of bias.

### Content description

• Students interpret and use logarithmic scales in applied contexts involving small and large quantities and change. AC9M10M02
• Students analyse claims, inferences and conclusions of statistical reports in the media, including ethical considerations and identification of potential sources of bias. AC9M10ST01

### General capabilities

Numeracy:

• Multiplicative strategies (Level 10)
• Interpreting and representing data (Level 8)

Critical and Creative Thinking:

• Interpret concepts and problems (Level 6)
• Select and operate tools (Level 6) – Optional activity

Ethical Understanding

• Explore ethical perspectives and  frameworks (Level 6)
• Explore ethical issues (Level 6)
• Making and reflecting on ethical decisions (Level 6)

Aboriginal and Torres Strait Islander Histories and Cultures: Country/Place (A_TSICP2), Culture (A_TSIC3) and People (A_TSIP3

The following exit ticket is given as an assessment opportunity.

• Download and print out Exit tickets. Note that there are four duplicate exit tickets per sheet.
• Ask students to imagine they are tasked with explaining today's lesson to a friend who missed class. How would they summarise the key points of the lesson using three bullet points?

Some students may:

• be unwilling or unable to estimate and be reluctant to make estimates about dates when they have no idea when an event occurred. Mitigate this by asking, ‘What is a number that is too big?’, ‘Too small?’ and encourage them to consult with their group.
• show a persistence for linear thinking. Checkpoints built into the lesson, and the provision of pre-drawn log graph paper, will help build students’ understanding of log scales. Use questioning extensively to consolidate learning, highlight misconceptions and promote rich discussion about the properties and purposes of representing data using a log scale.
• experience technology difficulties. If undertaking the optional digital activity, use internet searches to help identify how to change a linear scale to logarithmic, as different devices and spreadsheet packages will access this function differently.

Prior to this lesson, it is assumed that students have knowledge of:

• plotting points on a line graph using a linear scale
• index notation and powers of ten.

## What you need:

• Lesson plan (Word)

• Teacher's slides (PowerPoint)

• Card sets (Word)

• Log graph worksheet (Word)

• Exit ticket (Word)

• Rope (15m), lengths of string (5m) or chalk, scissors, calculators