This document provides a mark scheme for a modular mathematics GCSE exam from June 2011. It outlines the general principles that examiners should follow when marking answers, such as awarding full marks for correct responses. It then provides specific guidance on marking for each question on the exam, including what constitutes correct working and answers. The document is published by Edexcel, an examining and awarding body, to ensure consistency in how examiners apply the marking criteria.