OT2: Mathematical problem solving: Interpret and communicate solutions in the context of the original problem.

The idea

After solving a problem, you must relate your mathematical result back to the situation described. This means explaining what the numbers or expressions represent, using appropriate units, and checking whether the answer is sensible. For instance, if you calculate a negative time or a probability greater than 1, you should recognise that the model or calculation needs revisiting. Communication involves writing clear sentences that connect your working to the context, not just stating a numerical answer. You should also consider limitations of the model, such as assumptions made, and express conclusions precisely. This outcome is assessed through problems that require a final statement in context, often with marks for correct interpretation and clear communication.

What earns the marks

• Relating the final mathematical result back to the original scenario, stating what it means in everyday language.
• Using correct units and appropriate levels of accuracy when reporting the solution.
• Checking the reasonableness of the answer, including whether it lies within possible bounds for the context.
• Communicating the solution clearly with a structured explanation that a non-mathematician could follow.
• Acknowledging any assumptions or limitations of the model where relevant.

Common mistakes and how to put them right

• Giving a numerical answer without any contextual statement.

  Put it right: Write a concluding sentence that explains the result in terms of the problem.

• Ignoring units or using inconsistent units in the final answer.

  Put it right: Carry units through calculations and state the final unit clearly.

• Accepting an unrealistic answer without question.

  Put it right: Compare the result with the context, such as checking that a length is positive or a probability is between 0 and 1.

Exam tips

• Underline the actual question in the problem so your final statement directly answers it.
• Write your interpretation as a separate sentence after your calculations to ensure it is clear and creditworthy.
• If the context involves money, time or measurements, round appropriately and state the rounding used.