How to Get an A* in A-Level Maths

Just bought a Casio fx-83ES with Natural Display.
Natural Display is the best thing about new calculators. If I type

√12 + √27

The answer displayed is simplified to

5√3

How good is that?! Of course I can press one button to get the decimal answer of 8.66 as well.

I am also very interested in the Casio fx-115. Apparently it can calculate definite integrals (very useful for checking A-level answers).

I am a little bit concerned about this - the Edexcel syllabus says "Calculators with a facility for symbolic algebra, differentiation and/or integration are not permitted" in any of the exams.

Not sure if definite integration counts as symbolic algebra as the calculator probably does it by a numeric method. The fx-115 doesn't appear to do indefinite integration which I would say was definitely crossing the line. Will try to seek clarification from Edexcel!