# New GCSE maths - trial and improvement

Discussion in 'Mathematics' started by munkster, Sep 19, 2015.

1. ### munksterNew commenter

*Is* trial and improvement (the "too high/too low" way) in new GCSE maths (Edexcel if it makes any difference) or not? I was sure that it wasn't but now I'm not so sure. I thought the x=g(x) type iteration method had taken its place.

Anyone know? Many thanks in advance!

2. ### colinbillettOccasional commenter

It doesn't seem to be - I've checked KS3 and KS4 and no sign of it in the 2015 specs.

3. ### munksterNew commenter

Hmm, great that it is in my new textbooks just to confuse matters then! ;-)

4. ### Colleen_YoungOccasional commenter

I have just said on another thread - never rely on textbooks! Not for syllabus information.

5. ### munksterNew commenter

"Rely" is a bit of a strong word; I was merely checking what I believed to be true ;-)

6. ### Colleen_YoungOccasional commenter

Fair enough munkster! What we need of course is more papers!

7. ### PFCDazNew commenter

The DfE content says this only: find approximate solutions to equations numerically using iteration.

Which is repeated directly in the specs for Edexcel and AQA. at OCR we interpreted this in our spec as:

6.03e- Approximate solutions by iteration - Find approximate solutions to equations using systematic sign-change methods (for example, decimal search or interval bisection) when there is no simple analytical method of solving them. Specific methods will not be requested in the assessment.

That is to say, you may teach any structured iterative approach to solving equations, for which what we currently call trial and improvement would be permissible with a little modification, assuming the students record enough of their working to make it clear they have followed an iterative process rather than just a series of semi-random guesses to find a close answer. In the CUP textbook for the OCR spec, numerous possible methods are given, but we will not require any specific approach in the exam so it is up to teachers to decide whether to teach all of them or just select one, or teach an approach not in the textbook. Obviously I can't speak for the other AOs in terms of their approach to this section, but I would recommend contacting them directly for a detailed answer.