Mathematics Support Materials
Mathematics snapshot: Save our canteen
Mathematics/Statistics and Probability/Data representation and interpretation
|Content Description||Relevant aspects of the Achievement Standards|
Construct and compare a range of data displays including stem-and-leaf plots and dot plots (ACMSP170)
Students identify issues involving the collection of continuous data. They describe the relationship between the median and mean in data displays.
Students calculate mean, mode, median and range for data sets. They construct stem-and-leaf plots and dot-plots.
Nature of the assessment
Teacher observation of class activity
Purposes of the assessment
To assess students’ ability to summarise and display data in an appropriate manner; and to use graphs to inform decision making.
Stage in the teaching sequence
Mid-way in a lesson sequence
There had been some discussion in the school that the school canteen would only open for three days a week. As the students felt strongly about the issue the teacher decided to use it as a context to assess his students’ ability to work with data. However, he decided to mock-up data rather than to try to use actual data.
Context: The school canteen needs to save money and only open for three days a week.
Stimulus: A table detailing the canteen takings per day of the week, for an eight week period.
Task: The students were required to summarise the data in a table; use the data to construct a pie chart, a line graph and bar graph; explain which graph was the most appropriate for the purpose and make a recommendation for which three days the canteen should open.
- correctly summarises data
- uses appropriate scale
- accurately graphs data
- correctly labels graphs
- explains which is the most appropriate graph in the given context.
Using the information
The teacher marked the students’ work and gave detailed feedback. He also used the task to evaluate his teaching of the topic and made notes of teaching points as he marked.