Children's appropriation of academic register mathematics vocabulary is arguably essential for mathematics success in most contexts, and this is decidedly the case in multilingual Singapore, where word problems dominate students’ experiences with mathematics. Although English is the medium of instruction for Singapore mathematics classes, it is not the dominant language for a sizeable (but shrinking) portion of the pupils in most Singapore classrooms. The vast majority of Singapore primary school pupils, nevertheless, are able to achieve sufficient success in mathematics to enter academic streams. In this chapter, we discuss findings from a qualitative study examining teachers’ and students’ perceptions and experiences of teaching and learning primary school mathematics and English in Singapore. Presenting data from survey questionnaires, teacher interviews, and focus group discussions with pupils in primary levels one, three, and five at three different schools, we highlight the challenges teachers face in preparing their students for the emphasis on word problems in the Singapore context. Although numerous teachers admitted to using a ‘keyword’ approach in their classrooms, drawing straightforward associations between particular words and corresponding operations, some acknowledged that such an approach is problematic. This is especially the case at the upper primary levels, when problems become mathematically and linguistically more complex.