Abstract
Students are documented as struggling in high school with using formal proofs In particular, students believe that algebra is expected by teachers but is a component of responses not easily understood by themselves This research documented the use of algebra by 35 students from a range of high schools throughout New Zealand when responding to two justification question in an externally set end-of-high-school examination Although the numbers of students are small, some differences according to gender and socioeconomic background and question format suggest that further research needs to be done