Tag Archives: inverse

313. Friendly Functions

Just a quick resource share today!

I’ve been doing functions with my GCSE class as part of the new curriculum and I’ve gone down the algebra route. I could have started with graph drawing like the parallel class did, but I know my class – drawing and accuracy are not their forte. We made brilliant progress with substituting into functions and even composite functions went smoothly. I wasn’t happy with the textbook resources on manipulating functions so I put together a step by step resource, including a basic skills recap:

Manipulating functions (docx)

Manipulating functions (pdf)

I also thought my class needed a little hand holding for inverse functions. There are many ways to do this, but the method I used was designed to allow the class to access the topic with teacher input verbally and on the board.

Inverse Functions worksheet (docx)

Inverse Functions worksheet (pdf)

Hope these help!

Oh and you can even use them as A-Level recap tools.

Updated (19:53): To fix typo on Inverse functions worksheets

269. Snappy Proportion

Proportion … it comes in so many forms and different students grasp different elements at different speeds. Differentiation hell!

What about a little resource that offers up 4x8x8 variations of question ranging from simple direct to proportion to inversely proportional to the square? It’s not a new app, it’s an old app – a fortune-teller snapdragon:


Print, cut and fold (see 92. Snapdragon Fun for instructions)

  • The first decision chooses level of difficulty – students pick a number and count through the opening/shutting process.
  • The second gives the information to calculate k (eg y=kx) – the number of open/shut moves is specified.
  • The third asks you to apply your equation to a hidden number.
  • Students increase the level of challenge as they do more questions.

Download the pdf here: Proportion Snapdragon

The editable version is available here: Editable Proportion Snapdragon

You may wish to enlarge the pdf on a photocopier to make it more manageable for bigger hands.