To children going to school for the first time, the symbols and the vocabulary of mathematics can resemble a foreign language with its seemingly cryptic symbols and unknown terminology. This is a challenge to foundation phase learners' ability to read, write, and communicate clearly. It might be that problems of vocabulary are considered to be fairly superficial within the whole issue of language and mathematics learning, but it is nevertheless critical that such problems are not ignored in the hope that they will go away. Teachers must be purposeful in constructing learning experiences that direct learners' attention to specific words and their meaning. The aim of this article is to highlight the importance of including mathematics vocabulary code cracking as part of the pedagogical content knowledge, specifically the subdomains of knowledge of content and students, and knowledge of content and teaching, which should be addressed within foundation phase teacher preparation programmes.