Monthly Archives: June 2013

119. Inequalities Trashed

My colleague Jane introduced me to ‘Tick or Trash’ worksheets and they are just brilliant!


The basic idea is you have a table with three columns. The middle column is the question, either side are the solutions of fictional pupils. I called mine Kirsty and Kyle as I don’t teach anyone with those names. One solution is correct, one isn’t. Your students must decide who is right and why. They must then decide where the other pupil went wrong.

The worksheet I’ve put together is about inequalities. It covers using a numberline, solving a linear inequality with the unknown on one/two sides and dealing with a negative. There is also a QR code linking to a short YouTube clip (not mine) on solving inequalities. Download it here. The basic colour coded answers are available too. Note: the files are in docx format.

This is an ideal activity to use with the Validator concept. I would give my peer Validator the answer sheet to refer to, but the explanations would be down to the students to gauge if they understood.

118. App of the day

Do you ever play the numbers round from the TV programme ‘Countdown’ in class?

I was on a training course the other week and whilst chatting in a break Sarah – a fellow delegate, introduced me to the free android Countdown app. It is so easy to use a 6 yr could (and does) use it.


There are quick rounds, full games and practice mode. If you choose the number practice mode, you can randomly select numbers and it will even show you the solution. So you can use Countdown as a starter without scribbling numbers on a bit of paper and only being 10 seconds ahead of the class.

Download it from the android store by searching for ‘Countdown for Android’.

117. Circle facts

I sometimes despair when I read through students’ exercise books. A brilliant explanation or set of revision notes are let down by poor diagrams – especially when you are working on circle theorems. I’m also suspicious of handing out perfectly typed notes because I’m sure they don’t get properly read.

I’ve taken both these issues and put together a C grade Circle Theorems Fact finder sheet. The diagrams are printed, but the theories are missing. Students need to write the missing facts in their own words. This processing of information should consolidate their understanding.


Download it from here.

115. Decimate

Here’s a nice (gory) problem to use as a plenary.

What does the word ‘Decimate’ or ‘Decimation’ mean?

The word derives from Latin meaning ‘to remove one tenth’.


The original context is the punishment of a Roman Legion. The unit was divided into groups of ten and lots were drawn. The unlucky soldier was executed. A Cohort consisted of  480-500 soldiers, a Legion consisted of 10000 soldiers. How many would survive in a Cohort? How many would be executed in a Legion?

Now if the class were an unruly unit, how many would draw an unlucky lot?

A legend suggests that the Theban Legion was decimated in the third century AD. The Legion had refused, to a man, to accede to an order of the Emperor, and the process was repeated until none were left. They became known as the Martyrs of Agaunum (there are several sources on this).

Rather than execute your class I use this legend as a logic problem. Which pupil in the class is safe? Either the class stands, sitting when they are ‘executed’ or stand and then line up to leave. You can stop every few counts and ask who thinks they are safe. Last soldier standing leaves the lesson first!

Don’t have nightmares!

114. Pin Up Ideas

A quick resource idea for you today:


If you are not familar with Pinterest, it’s basically a digital pinboard of images, which usually have extra information or weblinks. There is a whole channel of education ideas – you can ‘Repin’ other people’s ‘Pins’ or upload your own. You can have several pinboards that are either public or private.

Go to Pinterest to browse the public boards. There are also official smartphone apps available from the appropriate stores.