# Level 2

## 91256: Apply co-ordinate geometry methods in solving problems

Updated December 2014. This document has been updated to address issues that have arisen from moderation.

### Solving problems

The problem needs to provide sufficient scope for students to demonstrate and develop their own thinking. If there are parts to the problem, all of the parts need to contribute to the solution.

A task with a number of discrete questions based on skills and straightforward calculations is not appropriate for students to demonstrate evidence of the required levels of thinking.

Students need to make their own decisions about what to do and how to solve problems. Where an assessment task has a series of instructions that lead students through a step or a sequence of steps towards the solution, it is likely the opportunity for students to demonstrate all levels of thinking will be compromised.

### Expected evidence for Achieved

For Achieved, the requirements include selecting and using methods. To be used as evidence, a ‘method’ must be relevant to the solution of the problem. The ‘methods’ also need to be at the appropriate curriculum level for the standard.

The evidence for ‘selecting and using methods’ cannot come from a situation where students are told what method to use so an instruction like ‘Find the equation of the line AB’ is inappropriate.

Any method that is selected needs to be used in the solution of the problem, for example, if a midpoint is found there needs to be evidence of it being used in the solution.

### Communicating solutions

At all grades there is a requirement relating to the communication of the solutions.

At Achieved, the result of a numerical calculation only is insufficient, working is expected and students need to indicate what the calculated answer represents.

At Merit, students need to clearly indicate what they are calculating and their solutions need to be linked to the context.

At Excellence, the response needs to be clearly communicated with correct mathematical statements and students need to explain any decisions they make in the solution of the problem.