Here are some reflections from my last post and lesson on significant figures:
1) Language – I think it helps the students grasp significant figures if you always ask them to round the number to 3 s.f as opposed to asking them to write a number to 3 s.f. This connects to my third point.
2) Context – I changed the first PowerPoint slide slightly to incorporate 2 examples that we could discuss. The first was rounding 78582 to three significant figures. After reading Claire’s comment I decided to put the lesson into conext by using the standard example of a football match attendance and the usual rounding of the number to 2 or 1 significant figure – thanks Claire!
3) Understanding – Some good advice from my HoD was to make sure the students have a sense of how big the number is in the first place. That way when they round a number to 3 s.f, they don’t end up rounding 436200 into 436! (This can and does happen at times with low ability). Use of number lines help with this.
4) Active Involvement – Since it’s a lesson on significant figures, it’s never going to set the world alight! However, getting the students up to the board to draw a number line, using mini-whiteboards to check understanding or just simply asking for the numbers from them is a simple way to get them involved.