The achievement tests in the 2011 Trends in International Mathematics and Science Study (TIMSS) were designed to assess the thinking processes that learners engage in when solving mathematics problems. The hierarchy of cognitive processes included three domains: knowledge, applying and reasoning. We examine these three cognitive domains and provide examples of questions that assess each domain. Although the overall achievement was low, with an average score of 352 across the three domains, South African learners surprisingly fared relatively better in questions that required reasoning.