Suggested steps

Learning hook

1. Use a quiz to stimulate interest in marine turtles and discussion of some key concepts.
2. Use a suitable learning hook to engage students in analysing and interpreting real data about marine turtles. Here are some ideas:
   • Share experiences of observing turtles when holidaying or visiting museums or aquariums.
   • Use a relevant resource such as Marine turtles in Australia to show images of different turtle species. Discuss what students know about turtle habitats, conservation status (vulnerable/endangered) and the cultural and social values of turtles for Aboriginal and Torres Strait Islander people.
   • Ask: What affects turtle population numbers?
   • ask students to hand draw a picture of a turtle thinking about its features and how these features help it survive.
     Compare their drawings to an image of a turtle or this flatback turtle in 3D.
   
   

Marine scientists

3. Discuss the work of scientists who work in conservation, surveying populations to ensure relevant data is collected, analysed and used to inform management strategies. Refer to career profiles for Sabrina Fossette of the Western Australian Department of Biodiversity, Conservation and Attractions and Blair Bentley, a postdoctoral researcher.

   
   

   
   
   
   

Student task

4. Use the slide deck, Marine turtle: nesting. The slide deck introduces the question: How many eggs might a female turtle lay in her lifetime? It provides a guide to scaffold students’ mathematic, scientific and technological thinking. To answer the question students need to know the total number of eggs a turtle lays in a season and how many seasons it nests and lays. Provide time for students to work out their own method of calculation.

   

Using data in their calculation

5. Provide students data when they attempt to calculate the number of eggs a female turtle lays in her lifetime.

   Use the following data for a leatherback turtle to complete the calculation.

   • Species: Leatherback
   • Current age: 50
   • Breeding age 15
   • Years between nesting: 5
   • Average number of eggs per clutch: 82
   • Average number of clutches per season 6.

Breaking down the calculation visually

6. Once the students have has a go at their calculation, use the flow chart to assist students to work out the calculation. Compare this with students’ initial thoughts on the calculation.

   The flow chart provides an opportunity to discuss this as a form of algorithm.

   
   

   Discuss the differences regarding the total number of eggs laid in a lifetime if certain factors were changed; for example:

   • if years between nesting were shorter or longer
   • if the average eggs per clutch were lower or higher
   • if the average number of clutches per season were lower or higher.

   Talk about the likelihood that only one in 1000 turtles survive. How many of a female turtle’s offspring would be likely to survive, based on those odds? (3423/1000 = 3.423 or 3 offspring).

   
   

Data modelling

7. Use the Turtle hatchling production modeller to calculate how many eggs a female turtle lays in her lifetime. Discuss the use of the spreadsheet to model an event like turtle hatchling survival. Discuss the green cells with inputs using drop down menus. Analyse the changes to the output cells. The spreadsheet allows students to enter different inputs to look for patterns in the data and predict outcomes based on changing parameters such as age of the turtle, breeding age, years between nesting, number of clutches per season and adjust the chance of survival of a hatchling.

   (Click on the image to expand it in a new window.)

   

8. The Turtle hatchling production modeller allows for differentiation.

   Level One

   Students use the interface to explore changing the inputs and record their generalisations, for example The older the turtle the more eggs it lays in its lifetime. These generalisations can be incorporated into a brief scientific report, which could include screen captures of the modeller.

   
   Level Two

   Students familiar with spreadsheeting software, such as MS Excel, Numbers for iOS or the browser-based Google Sheets, can create their own modeller. Students can use the algorithm to explore how the cells are linked. Copy a row of data and paste for a different species. Adjust the formula in the cells and data in cells for the particular turtle species, referring to the table below the algorithm, scientific data. Students can create lists for the drop down menu using the table in the workbook tab. Students will use data validation for the input cells. Conditional formatting has also been sued to Fill the output cells in red if the breeding age is a negative number. Test the model and adjust as required.

   (Click on the image to expand it in a new window.)

   
   
   Level Three

   Create their own interface for their chosen turtle species. Students consider what cells have input, which cells are hidden and how the output is displayed. They consider the use of images, font size and how data is displayed.

9. Share students’ modelling of the data and what they learned. Ask them to consider global issues such as:
   • plastics pollution in the ocean
   • climate change and impact of rising temperature on turtle nesting.

Creating an infographic

10. Ask students to do some further research and create an infographic about turtle conservation incorporating the data they used in their data modelling.

Discussion

Digital Technology focus

• How can spreadsheets be used to model population data?
• What is the benefit of using a spreadsheet to model the data?
• How can you design the spreadsheet to be user friendly?

Science focus

• What factors affect the turtle population?
• The likelihood is that only one out of a thousand hatchlings will survive. How does that affect the population numbers of marine turtles? What might happen if that chance of survival decreased?

Mathematics focus

• How do you calculate the number of eggs a turtle lays in her lifetime?
• What operations do you include in the process?

Why is this relevant?

In Digital Technologies, students need to interpret data. To do this it helps to organise the data in some way; for example, in a table under relevant headings. In a spreadsheet, students can sort and filter data to look for patterns or trends.

Students present data to reveal information and convey meaning. Students can do this by developing visualisations such as graphs, tables and plots to reveal trends. In years 7–8, students model objects and events. This task allows students to model population data and infer relationships and effects of changing inputs.

Resources

Turtle slide deck (student task)

Turtle hatchling production modeller

Flatback turtle in 3D

Leatherback turtle nesting activity

Turtle quiz