There are three main strategies we use to teach students to help them add or subtract 2 or 3 digit numbers mentally.
- Jump
- Split
- Compensate
We teach the students that it doesn't matter which strategy they use, as different ones work for different people and for different types of questions. The idea is to understand the different strategies and choose one that works for them at the time! This article will focus on the Compensate Strategy.
Compensate Strategy - requires the user to adjust one number (building up or building down) to make a number more friendly or easier to work with, then add or subtract the parts and adjust the sum (or difference).
How can I help my child at home?
- Give them numbers close to a "ten" to round up or down to the nearest ten eg 9-10, 48-50, 61-60, etc to give them practice at seeing numbers flexibly.
- Play games or set yourself challenges where all members of the family add or subtract numbers (1, 2 or 3 digits) together and all share the strategy you used to calculate them. Talk about the way you may have used a different strategy, to get to the same answer.
If you have any questions about this strategy or any other Mathematical questions, come along to the Maths Masters Club every Friday morning 8am-9am in the Library (2016). This is a time for parents to learn as well as children!
Happy calculating.