This comparative research study examined Grade Five Malaysian Aboriginal pupils' mathematical performance on 30 computation and 20 word problem items in the academic Malay language and community "Temiar" language. The items were constructed in the Malay language before adapting and audio recording into the "Temiar" language using experienced Mathematics teachers and native speakers. One test consisting of monolingual test items written in Malay language (MAL) and, another bilingual test with audio test items in "Temiar" language and written items in Malay language (BCL) were constructed. These two tests with identical content validity, were administered spirally among 237 pupils from eight schools in two states. Findings indicated that for computation and word problem items, pupils found the BCL test easier. They performed significantly better in computation items than in word problem items for both tests, with Cohen's d medium to high effect. The community language helped to alleviate the linguistics complications.