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Activity: Forensic formulas

AOs | Indicators | Learning outcomes | Snapshot | Learning experience
Cross curricular | Assessment | Spotlight | Links


Students will relate tables, equations and graphs to find relationships in a forensic context.

Achievement objectives

  • NA6-5 Form and solve linear equations and inequations, quadratic and simple exponential equations, and simultaneous equations with two unknowns.
  • NA6-7 Relate graphs, tables, and equations to linear, quadratic, and simple exponential relationships found in number and spatial patterns.
  • NA6-8 Relate rate of change to the gradient of a graph.


  • Solves problems which can be modelled by linear equations and inequations, quadratic and simple exponential equations, and interprets solutions in context.
  • Uses algebra and graphing for solving linear equations and inequations.
  • Makes connections between representations such as number patterns, spatial patterns, tables, equations and graphs.
  • Understands that change of one variable with respect to another can be represented in various forms such as a table, an equation, or in words.

Specific learning outcomes

Describing forensic data using tables, formulas and graphs.

Diagnostic snapshot(s)

Forensic scientists use formulas like those below to find the height of people from their tibia bone.

H = 81.788 + 2.4t H = 72.64 + 2.5t

Guiding questions:

  • What other information can you get from the formulas in this table?
  • Can you draw a graph of these formulas?
  • What do the formula mean? (gradient? y-intercept?)
  • Why are there two different formulas?
  • How would you go about testing these formulas?

Planned learning experiences

  • Activity: Measuring bones to predict height (worksheet)
  • Students collect own data and test whether the above formulas are true (extensions – children vs adults/amount of data required).
  • Students collect data on radius/humerus bones and generate a formula of their own to predict height.
  • Students compare their formula to the following:

H = 73.66 + 3.0h

H = 80.518 + 3.7r

H = 65.024 + 3.1h

H = 73.406 + 3.9r

  • Recap of drawing linear graphs from formula.
  • Linking gradient of graph to the ‘m’ in y = mx + c to its meaning in this context (use of academic language).
  • Discussion about correlation / scatter plots, leading to linear relationships.

Possible adaptations to the activity

This task is linked to finding models of ‘real-life’ data.

Conjectures about body measurements could also be made from a picture of Vitruvian man, and the link between proportions such as width of the shoulders is a quarter of a person’s height to data and equations such as h = 4 and w = 14h.

The activity could be extended into a look at the body measurements and Vitruvian man from a statistics focus. See  CensusAtSchool: Masterpiece 2; CensusAtSchool: Masterpiece 3.

Cross curricular links

  • Science – Physics AO / AS
  • Art – Use of canons for sculpture

Planned assessment

This teaching and learning activity could lead towards assessment in the following achievement standards:

  • 1.3 Investigate relationships between tables, equations or graphs.

If a statistics focus was taken then the following achievement standard could also be considered:

  • 1.11 Investigate bivariate numerical data using the statistical enquiry cycle.

Spotlight on


  • Enhancing the relevance of new learning:
    • Encouraging students to explain their thinking.
    • Structuring mathematical discussion and argument.
  • Making connections to prior learning and experience:
    • Checking prior knowledge using a variety of diagnostic strategies.
    • Providing real-life problems in which the context is relevant to students.
  • E-learning:
    • Using technology to explore concepts.

Key competencies

  • Thinking:
    • Students hypothesis, investigate, analyse and evaluate.
    • Students deal with uncertainty and variation, they seek patterns and generalisations.
  •  Using language, symbols, and text link:
    • Students use the language of algebra to communicate and reason.
    • Students use symbols and diagrams to solve problems.


  • Students will be encouraged to value innovation, inquiry, and curiosity, by thinking critically, creatively, and reflectively.


  • Ka Hikitia
  • Pasifika Education Plan
  • Caution: In some cultures forensic information could be seen as inappropriate, so the context could be adapted to a focus from the Vitruvian Man angle.
  • Exploration of dimensions of sculpture in these cultures would also be a good starting point.

Planning for content and language learning

  • ESOL Online
  • Provide multiple opportunities for authentic language use with a focus on students using academic language:
    • Is the language focus on key language?
    • Do I make sure the students have many opportunities to notice and use new language?


Download a Word version of this activity:

Activity_Forensic formula (Word, 120 KB)

Last updated July 30, 2015