The purpose of this multi-level task is to engage students in using proportional reasoning to find a solution to a problem in context.
The background knowledge and skills that need to be established before and/or during this task are outlined in the diagram below:
This task may be solved using calculations finding the lowest cost per month or by taking further factors from the context into consideration. The approach should be chosen in sympathy with students' skills and depth of understanding.
The procedural approach (show more)
- The student is able to calculate the different costs of data bundles for the required usage, to recommend a purchase plan.
Prompts from the teacher could be:
- For each of the bundles on offer, consider how many bundles will be needed to make up 7GB of data. Calculate the cost of purchasing 7GB of data for each of these offers.
- Given that the carry over period for unused data is another month, consider the cost of purchasing 14GB of data over two months. Then work out the cost per month of such a purchase.
- Find the best deal for Sally.
The conceptual approach (show more)
- The student is able to use the context alongside calculation of the costs of data bundles, to find the optimal solution.