I've owned the Casio FX-83ES for as long as I can remember. I actually own the solar panel version but in principal it is the same calculator. The FX-83 has served me through my GCSE's, A-Levels and through my first 3 years of university and unless something drastically changes it will be there throughout my fourth and final year of university.

There are numerous reasons why I've stuck by this calculator for so long. In short; it has a fine balance between simplicity and ease of use but also offering more complex advanced abilities to those who study more difficult topics. The calculator comes packaged with a handy manual but for anyone who regularly uses a calculator knows that the best way to understand one is to use it repeatedly. Within minutes of first using it I was able to accomplish everything I needed.

The replay function is very handy and lets you work back through a calculation if something went wrong. It stores at least 10 of your previous commands (Without you having to save them) so you can always flick back to see what you've done in the past. The calculator comes equipped with 7 memory slots which should be more than enough for students. The calculator naturally expresses the answer in either fraction or square root form which means the accuracy is always of the highest order. I know a lot of people don't like this; they much prefer the answer as 31.34848 for example. However the press of one button will change the answer from exact form to a regular number.

The calculator itself looks pretty snazzy. I know calculators aren't exactly a fashion trend but comparing this to other calculators out there it looks modern and slick. There are some horribly retro looking ones out there which make them look like a brick. This one is slim and lightweight and the sliding cover doesn't stick. The dark background and buttons is also much nicer than the light coloured ones which normally have bright green/pink buttons.

The buttons are cleverly colour coded for ease of use. Cancel/delete are red whilst all the options/menu/control buttons are in blue. The numbers and basic functions (Add, subtract etc) are in dark black whilst more advanced functions (Trigonometry, log, square root etc) are smaller and in a dark shade of blue. This makes finding the right button a doddle. The buttons are clearly labelled including their shift/alpha alternatives.

It's also worth mentioning that these labels don't fade. I've had my current calculator for about 5 years and none of the paint work has come off or scratched. As a device it is generally very robust. There are no signs of wear and tear. None of the plastic has been damaged or started to crack. Often the case begins to show signs of heavy use but the FX-83ES is strong and can withstand a bit of a beating. It's a similar story for the battery life. I have mentioned that mine is the version with the solar panels however I doubt they add that much extra life. The battery has yet to fail in over 5 years of use. At school I studied Physics, Maths and Further Maths and I've gone onto to study Engineering at University so as you can imagine I've spent a fair few hours using this calculator! I always carry a back up for exams but so far there's been no need for it

Having studied the subjects mentioned I've needed a high quality calculator with a lot of functions and so far the FX-83ES has yet to fail me. Whether its advanced trigonometry (Sinh, cosh etc), logarithmic equations or working in radians the calculator has been an absolute breeze to use. Not once have I needed a more advanced calculator. The FX-83ES isn't a graphic calculator which is probably it's only set back however a graphic calculator is only realistically by a small group of people. What's best about this calculator is it meets the legal requirements for GCSE, A Level and University exams. The laws for what you can and can't take into an exam are becoming increasingly finicky but the FX-83ES meets all the requirements meaning exams are just that little bit easier with one of these by your side.

So in summary it is a very useful calculator that is very easy to use. It is appropriate for school students as well as University students. The battery life is huge so buying just the one could last you 5-6 years. It's very accurate and exact but not too daunting and scary for younger children who want a simple answer. And for those who like to muck about on a calculator you can write any letter in the alphabet apart from T or V (Don't deny it, we all have before at some point!)