2.3.2.3a - Contribution

Calculate contribution as selling price minus variable cost per unit.

Use a - contribution to connect the rule to the data and decision in the question.

This matters because a - contribution determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply a - contribution to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: a - Contribution is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.