The aim of this study is to study the validity and reliability of the SBS-2008 7th grade Mathematics sub-test. The psychometric characteristics of the items and tests have been studied with this aim. Exploratory and confirmatory factor analysis along with structural validity has been studied under the validity study whilst the internal consistency (KR-20) reliability and two halves reliability (test halving) has been evaluated. At the end of the exploratory factor, it has been monitored that the 12th item of the Mathematics sub-test consisting of 18 items, works under a single factor. The consistency benefaction indexes obtained at the end of the confirmatory factor analysis shows that the model-data consistency is high. The KR-20 reliability coefficient has been calculated as. 72 whereas the reliability coefficient related to the first half of the test has been calculated as .52 and reliability coefficient related to the second half has been calculated as .56. (C) 2010 Elsevier Ltd. All rights reserved.