They found that reasoning terms such as explaining were used by all teachers and proving by three quarters of the teachers but terms such as contrasting, transferring or deducing were less commonly used. This indicated that teachers integrate only some aspects of reasoning in their teaching but it was less clear which aspects. Their study however, does not reveal the depth of teachers understanding of reasoning, what examples of reasoning are evident in their classrooms, and whether teachers are aware of the differences and relations between the four proficiencies: understanding, fluency, reasoning and problem solving