# Effective use of the Classwiz calculator

Thursday 9th January 2020

After analysing the 2019 examination papers, several teachers asked for support in using the Casio fx-991EX Classwiz effectively, both within a classroom and examination environment. There seemed to be some confusion over what the calculator was capable of doing and when these features could and couldn’t be used in an exam question.

Therefore, we ran a Classwiz focused session, during which the teachers were shown the excellent QR code option which allows this scientific calculator to be used as a graphical calculator simply via the use of a smartphone. An example of this exciting facility is shown below:

- Select
`MENU` - Select
`9`(9:Table) - Type \(f(x)=x2\) (using buttons
`\(x\)`and`\(x2\)`), then`\(=\)` - Type \(g(x)=2x\) , then
`\(=\)` - Enter these: Start: \(0\), End: \(5\), Step: \(0.2\), then
`\(=\)` `SHIFT`->`QR`(above`OPTN`)- Open CASIO EDU+ app
- Select QR code
- Scan the code

The group then looked at a range of A level topics for which the calculator could be used to find a quick, reliable solution. These included summations, definite integrals, equation solver, modulus equations and curve sketching via table mode (see above).

The group then had a detailed look at a range of examination questions and the advice offered by the examiner’s comments. These included examples such as:

- When attempting to show that a cubic polynomial could be factorized…“There was also clear evidence of using calculators to find the roots, followed by an attempt to work backwards to obtain the factors; this was unacceptable”.
- When required to solve a cubic inequality…“The most straightforward way to answer the question was to expand the cubic and solve the inequality directly on a calculator to obtain all 3 marks”.
- With any uncertainty over an answer…“The use of calculators to check answers should be encouraged.”.
- Candidates should be encouraged to take care with their sketches and… “Given that calculators are available to check the basic shape (either directly plotting or using the table function)”.

There are many excellent resources on the MEI website and support with using graphical calculators. Future KS5 network meetings are shown below and booking details can be found on the AMSP webpage.

**Manchester**

- Modelling opportunities in lessons – Tues, 4
^{th}February - Proof reasoning and command words – Tues, 10
^{th}March - tbc – Tuesday, 21st April

**Liverpool**

- Modelling opportunities in A-level maths – Tues, 14
^{th}January - Proof and command words – Tues, 17
^{th}March - tbc – Tuesday, 28
^{th}April

By** Mike Baxter**