Efficient Calculations : Addition and Subtraction

Download the PowerPoint here

I was going through my old PowerPoint slides looking at my column addition and subtraction stuff. Which was fine, I guess. But I’ve abandoned using slides for a lot of that stuff and set up examples using mathsbot’s place value counters. They’re awesome. (Although I’d like to be able to save an example for later use). I then use loads of randomly generated questions. Usually I’m a fan of writing my own questions, but randomly generated addition and subtractions, especially if you put them in a crossnumber are where it’s at.

What I like talking about, though is efficient calculations. I’ve extracted them and made them into their own lesson here. I really believe in talking about this stuff. My year 7s will sit for ages and work out a calculation left to right without even thinking about number bonds.

We’re sometimes so tied to hitting examable objectives that we forget this stuff can be really powerful. My ideal year 7 scheme of work would move away from these skills and move onto covering things a bit more nebulous like ‘Tricks’ or ‘Diagrams’ (drawing bar models etc) so by the time we’re in year 8, we are all efficient and able calculators. I’d also add loads of binary and bases stuff. I don’t really care that it’s not in the GCSE. Stuff can be valuable without being a examined skill in the GCSE.