Mental computation is the process of drawing on known
strategies to solve an arithmetical problem. For example, to find 17 + 8, a
strategic approach would be to split the 8 into 3 + 5 because you know that you
can now bridge through 10 to reach the answer of 25.
This book suggests activities that support mental
computation by exploring the Natural
Maths Strategies posters that can be printed from the accompanying CD. The
posters present the strategies such as bridging through 10, compensating and
number splitting as well as representations such as chunking, the open number
line and zigzag. Knowledge of these strategies and representations ensures
that, in a situation where memory fails or the numbers are too large, the
individual has the confidence to use mental computation to derive the answer.