A "National Numeracy Report" and the Australian Curriculum (2014) have recognised the importance of language in mathematics. The general capabilities contained within the "Australian Curriculum: Mathematics" (2014) highlight literacy as an important tool in the teaching and learning of mathematics, from the interpretation of word problems to the discussion of mathematics in the classroom. The nationally commissioned "National Numeracy Report," recommended that the language and literacies of mathematics be explicitly taught since language can be a significant barrier to understanding mathematics. As teachers routinely assess students' understanding of mathematics through literacy (often through reading and writing), students may struggle to understand the mathematics because they have specific language difficulties associated with assessment tasks set. Chapter 2 of the "National Numeracy Review Report" highlights the role of language in mathematics learning, and identifies a number of features of language that can have an impact on understanding mathematics. This article focuses on words in mathematics, their derivation and meaning.