Tasks | Early Adolescence | Negative Numbers

Tasks - Year 8, 9

Negative Numbers   by Richard Grey, Curriculum Council

Phase of Development:   Early Adolescence

Learning Area/s:	Mathematics, Science
Strand/s	Substrand/s
Number	Understand number
Chance & Data	Collect & Organise Data Summarise & Represent Data
Working Mathematically	Mathematical Strategies Apply and Verify
Measurement	Understand Units
Brief Description:	Students collect data on height of balloon and temperature then plot data on a graph.
Expected Outcomes:	Calculate changes in temperature with height then tabulate results on a graphics calculator. Plot data using the graphics calculator, choosing suitable scales. Recognises and understands the need for negative numbers.
Context:	This activity is designed as an introduction to negative numbers. Students are required to tabulate data using statistical mode on a calculator then graph the results.
Learning Activities/ Experience:	Used as an introduction to negative integers. ( 15 minutes) Links to the Science learning area. Each day weather balloons are released into the atmosphere from Perth airport. Balloons are released at 6 hour intervals, the first being released at 6am. The balloon rises to about 28 000m and measures wind speed, wind direction, temperature and pressure. As the balloon rises, both the pressure and temperature decrease. As the pressure decreases the balloon will expand and eventually burst. In summer the temperature drops at a rate of about 1oC every 200m. 1. If the temperature at midday in Perth is 30oC fill in the table in the statistics mode on your graphics calculator. Height (m) 0 200 1 000 5 000 10 000 20 000 30 000 Temp (oC)               2. Plot the data as a line graph on your graphics calculator. 3. Estimate then calculate when the temperature of the balloon drops to freezing point.