Mental Calculation receives no special attention in school curricula and it has been often reduced to rote memorization. Nevertheless its study has shown relevance to the comprehension of specific cognitive processes with direct implications for mathematical education. Strategies used take form of theorems in action (Vergnaud, 1985). This study investigated the strategies of mental calculation used by a sample of 160 elementary school children from first to fourth grade in public and private schools. The results confirmed the use of multiple strategies in addition and subtraction problems. The holistic, flexible and active nature of mental calculation was also evident. This study contributed to a better understanding of children’s construction of mathematical knowledge. The results are also discussed with respect to educational applications.
Addition; subtraction; mental calculation