Successive Discounts
| Grade | Work Samples |
|---|---|
| End of Stage 5 (end of Year 10) | |
| Grade A | Frances(A10) Pat(A9) |
| Grade B | Cam(B7) Riley(B7) |
| Grade C | Lindsay(C6) Lou(C6) Ricky(C5) |
| Grade D | Bobby(D4) |
Description of activity
Students will answer the following questions:
1. Is a discount of 10% following a discount of 15% the same as a discount of 25%?
Justify your answer, giving examples and reasons.
2. What is the difference (if any) between the two discount situations?
Extension:
3. Is a discount of 10% following a discount of 15% the same as a discount
of 15% following a discount of 10%? Why?
Context
Number, Working Mathematically
This assessment activity could be presented to students at the end of a unit on Consumer Arithmetic, where students have been finding discounts and investigating the effect of applying successive discounts to a price.
Areas for Assessment
- Working mathematically
Knowledge, skills and understanding developed through inquiry, application of problem-solving strategies, communication, reasoning and reflection - Number
Knowledge, skills and understanding in mental and written computation and numerical reasoning
Outcomes
Consumer Arithmetic (NS5.2.2)
Solves consumer arithmetic problems involving compound interest, depreciation and successive discounts
Questioning (WMS5.2.1)
Asks questions that could be explored using mathematics in relation to Stage 5.2 content
Applying Strategies (WMS5.2.2)
Selects and uses appropriate problem-solving strategies that include selecting and organising key information and identifying and working on related problems
Communicating (WMS5.2.3)
Uses appropriate mathematical language and algebraic, statistical and other notations and conventions in written, oral or graphical form
Reasoning (WMS5.2.4)
Uses mathematical arguments to reach and justify conclusions
Reflecting (WMS5.2.5)
Links mathematical ideas and makes connections with, and generalisations about, existing knowledge and understanding in relation to Stage 5.2 content
Criteria for assessing learning
(These criteria would normally be communicated to students with the activity.)
Students will be assessed on their ability to:
- demonstrate knowledge and understanding of successive discounts
- generate and solve problems involving successive discounts
- communicate mathematical ideas.
Possible prompts to assist student engagement
- What is the first question asking?
- Can you make up some specific examples to illustrate question 1?
- Is it better to buy an article with a 25% discount or the same article with a discount of 10% following an initial discount of 15%?
- Try finding the discounts for each case for a particular sum of money.
Suggested materials
Pen and paper, calculator