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Monday, 26 April 2010 | 6 Comments

How do you make a unit on percentages richer / project-based / engaging / authentic?

A unit on percentages is one of those where I struggle to connect the messages of far greater “educators” than I with the reality of my classroom. I stick with a fairly standard approach to percentages:

- Intro – defining percentages, percentages ↔ fractions (denominator of 100).
- Simple fractions to percentages and common percentages.
- Percentages as decimals and vice versa.
- Finding a percentage of a given quantity.
- Comparing like quantities by converting to a given percentages.
- Profit/loss as a percentage of cost/selling price.

- Real Life problems (really just the same as above using the calculator).

We try to focus on not using a calculator, but rather using a knowledge of common percentages or other mental methods.

In “real-life” percentages are usually already solved for our students – not always correctly though.

The most interesting activity in this series of lessons comes at the end when we consider The Biggest Loser, however – to be honest – the way I’ve presented this only allowed maybe the top 2 students in a class to achieve, certainly needs a re-work for this year.

This is my problem, rich / project / authentic tasks seem to pitch themselves above the capabilities of an average mixed class at my school. Usually meaning that an attempt to undertake such an activity results in a more teacher-led lesson than normal. I say this is *my problem*, because obviously I need to find/create/borrow activities and ideas that are better suited to my students. But, they just don’t seem to be out there.

So, how do **you** make a unit on percentages richer / project-based / engaging / authentic?

*This is the sort of question I hope anyone can pose on my new Q&A site for maths teachers – a work in progress.*

Posted in • How to • Lesson Idea • Percentages | Short URL: http://mths.co/1816

**Simon Job** — eleventh year of teaching maths in a public high school in Western Sydney, Australia.

**MathsClass** is about teaching and learning in a maths classroom. more→

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