Mental computation: The benefits of informed teacher instruction

This study investigated the change in student mental computation strategies for addition and subtraction following eight half-hour lessons over an eight-week period The principal researcher provided the teacher with a theoretical background for mental computation and support materials for the development of the instructional program Twenty-one Year 2 students participated in pre- and post-testing using individual interviews to identify the students ’ mental computational methods The results indicated that students who employed inefficient methods such as counting moved to more sophisticated strategies such as wholistic compensation Other students who already employed some sophisticated strategies increased their repertoire In Queensland schools, written arithmetic procedures for addition and subtraction have traditionally been introduced at an early stage Typically, children in Queensland are expected to be able to calculate two-digit addition and subtraction written algorithms b