Morrisons M Chicken+Bacon Pasta Bake, 400 g

I bought the older version of this calculator 5 months before my GCSE maths exams. Even at this level I felt at a massive advantage: you can type in equations like 3y+1=5 and it will solve them. It also has a special mode which solves quadratic, cubic and simultaneous equations. Another time saver is when you want to repeat the same operation multiple times rather that scrolling along them replacing the number, for example if you wanted a list of what the value of a number cubed minus its value squared rather than entering 2^3 - 2^2 then 3^3 - 3^2, 4^3 - 4^2 ect. You could just: 1. Enter X^3 - X^2 2. Press CALC 3. Enter the value you want X to be and press = 4. Repeat steps 2 and 3 for whatever values you want With a medium sized function which you need to input say ten values you could more than quarter the time. I have just finished AS level maths and the new functions that are useful are non-symbolic integration and differentiation this means you cannot derive X^2 to 2X (calculators which do this are banned in UK exams) but you derive the function X^2 when X is 3, to equal 6. It also solves logs to the base of any real number as well as calculating the sums of sequences using the sigma notation. The applied module it took was statistics and for this you can just enter the data you have been given and it is able to calculate the values for linear regression lines the PMCC, Sxx Syy Sxy, min max, mean, range etc. It can do other types of regression but I have no use for these yet, in fact I have not use for most of the features of this calculator and it's still incredibly useful, it can do so much means it's probably the calculator of choice from GCSE to PhD. Even though I have a graphic calculator I use this 99% of the time for shear ease of use. Even when preparing for the non-calculator exams like some GCSE papers and core 1 (C1) at A-level this is useful as you can check your answers quickly or if needed do your homework very quickly on the bus to school. I would like to say this calculator is no substitute for hard work and proper understanding of the concepts. While it is true you only will really be able to use this calculator with ease and unlock its potential if you could do a question without the calculator if required and I would only recommend using it as a time saver, especially if you want to do a maths related degree. That said it can still get you marks where you shouldn't deserve them. At GCSE level they gave marks if the correct answer was seen even if no working was shown. So for one 5 mark question I did just that and I think got it right. Then at A-level I was stuck on one part which upon using the cubic equation solver showed me the correct method. These small marks could be the difference between whether a university accepts or rejects you, which for only [...] is a bargain. Just to finish a note of the differences between normal and the PLUS version. I terms of build quality there is very little difference. The new one is slightly more stylish. Functionally the PLUS version will show the answer to quadratic, cubic and simultaneous equations in surd form which the older model doesn't, this can earn you marks on some exams that require a surd for answer for the next question. This calculator is top of its range but lower models have features which this one doesn't: The two main cheaper models amazon currently sell (as of 08/2011) are the Casio FX-83GTPLUS Scientific Calculator and the solar powered Casio FX-85GTPLUS Scientific Calculator (also in pink) they are able to do prime factorisation, recurring decimal and verify inequalities. I am not sure why the 991 does not have these functions but perhaps it is so more useful features aren't compromised for calculations which can be done easily enough already. If you are buying a calculator for secondary school for the first time buy this, but don't exploit it. If you already have a basic scientific calculator already then keep it but buy this one or a newer version before your first important exams. 2011 UPDATE: Having completed my A-levels I found that for Core 4 the vector mode was useful. If you do further maths then this calculator is extremely useful as it can do complex number calculations including squaring and cubing in a way that I find much faster to enter than on a graphical calculator (but it cannot do square or cube rooting). It is also able to convert between algebraic and polar form, in other words find the modulus and argument of a complex number. Finally it has most (A-level) Matrix functions such as inverting which are useful to check your answers with.

Prior to this calculator, I used a Casio FX 991 ES (an old model). After losing it, I decided to upgrade to the ES-Plus. I was pleased to have upgraded -- the ES-Plus is a fully featured calculator yet the features are not too intrusive to hinder every day, 'casual' operations (such as simple addition). When wanting to do something a little more complex (e.g. complex numbers, vector products, matrices etc.), a simple shift into a different mode and the calculator becomes even more powerful. A particular feature which is useful for the GCSE mathematician is the equation solving function (which can be used to check an answer after working it out by hand) -- this can be used to solve linear, quadratic and cubic equations. For AS and A2 mathematicians, the statistic functions (such as regression) are useful -- regression calculations can take a lot of working, so it's satisfying to be able to check that you're right using a calculator function! Complex/Imaginary modes and vector modes are particularly helpful in Further Pure modules. Another feature which I found useful is the 'table' function -- this allows you to calculate a series of values for a certain function in a certain range. I have used this many times in Further Pure 2 when having to draw polar graphs! Arguably, the build quality isn't superb, but you have to remember that this is one of the cheapest calculators you can buy: and for how powerful it is, it is certainly worth it.

Perfect

Casio has always been my favourite calculator company (I haven't had the pleasure to play with a Texas Instruments). I purchased this calculator almost a year ago for my first A-Level calculator exam (Core 2)to replace my fx-83es that I used at GCSE, and have never looked back. It has all the functions of the fx-83es (natural display, scientific functions, radians etc) and so much more. the main differences between the fx-83es and the fx-991esplus are as follows: Integration and differentiation is a main selling point for me. Calculus functions are only numerical, so are only useful for checking you have the right answer (you still have to put in the hard work to learn how to integrate and differentiate). calculus functions do not work on parametric equations, though. The CALC function allows you to enter any equation (eg f(x)=4x³ - 6x² + 7x -4) and substitute values of x. Essential for trial & improvement, remainder theory, etc. The equation function allows you to enter simultaneous (with either 2 or 3 unknowns), linear, quadratic, and cubic equations to find all your values of X, Y and Z (Y and Z on simultaneous equations only). The SOLVE function is only useful on linear equations, as it only provides 1 value of x. Although, its trial and improvement algorithm will allow you to use trig functions. The calculator is pre-programmed with 40 scientific constant, with a legend on the inside of the case. As a physics and chemistry student, this has saved me from having to flick through the formula book during exams, saving valuable minutes. Having constants pre-programmed into the calculator also means I can't make a mistake in using the wrong constant, or copying it down incorrectly. The calculator does have a complex number mode, although as a normal maths (not further maths) student, I have never needed to learn how to use it. However, the reason I gave the fx-991esplus 4 stars and not 5 is that the build quality does leave some to be desired. Although it has withstood the abuse that comes from being by a student's side for a year, the plastic feels a bit flimsy, and at first glance, it looks like something from the 1970s - otherwise it would be a perfect non-graphic scientific calculator. The bottom line - This is an essential calculator for any student studying maths or science (or both) at A-Level. It won't do your maths paper for you, but it will allow you to make sure you have the right answer, so you can go back and trace your mistakes. Make sure, however, that you pop the calculator case back on before you throw it into your back at the end of lessons - otherwise, the build quality might let you down.

It was my calculator for uni, as I had to downgrade from the graphical calculator for exam compliance. If you're familiar with other Casio calculators this one should feel very intuitive. Battery lasted my whole degree. The calculator had some of the matrix calculation features that saved me lots of time during exams. I've used it few years ago, so might be worth a check if there isn't a newer model available. Also check with your university/school what models are allowed.

After 12 years of real-world use, I’d recommend the Casio FX-991ES Plus as a very capable, reliable, and affordable scientific calculator. It is equally suitable for students and general users who need advanced math functions without paying for graphing capabilities. It’s excellent for day to day coursework, gives clear, textbook like displays, and rarely lets you down thanks to its dual-power design. However, if you specifically need graphing, faster processing, or more modern navigation, you might consider the newer Casio FX-991EX or other advanced models. For most users whether professionals or learner this is a very dependable workshorse. Battery life is excellent as I had to only change it once in all these years. PROS! * Text book style display. * Extensive funcitionality. * Reliable battery life with dual power (Solar and backup LR44 battery). * Lightweight and portable. * Excellent value for money. CONS! * No graphing feature. * Menu navigation can be slow. * Very dated design. * Very expensive the newer model is selling for $25. * Doesn’t offer any other colour.

Although I think this calculator is not perfect, I gave five stars because nothing comes close as far as I know among calculators you can use in exams. The good: The natural display make it much easier to use than other calculators and has a range of very useful functions. Some of which like (CALC) and sum function will save time in the exam, some others like numerical integration, differentiation lets you double check your calculations so that you can be absolutely certain that they are correct, and notice any errors. There's a useful guide how to make the most out of it: [...] The bad: The main issue is the limited hardware. It's annoying to find I can't type in an iterative expression because there's a character limit of 99 characters. Similar frustration occurs when memory is dumped when changing modes, or can't see the history for as many calculations as I want. Or when I can't just use vector calculations as I want fractions and vectors only work with decimals. It's also annoying that in vector mode using variables is more complicated and you only get 3. I found it a bit disappointing that there's no product function, even though the manual says so. Once you use one of the non-standard modes it starts to get a bit complicated and time-consuming to deal with the menus. You can only use the natural display in the standard mode. (you have to use conventional linear display in the others). A good example of complicated menus is the vector mode (part of A-level maths): Every vector operation requires you to press 3 buttons: (shift) + (5) (gives the list of options to choose from) and a number next to the option you need. For example for the dot product you can't just press the decimal dot button, you have to go through the same menu. You can choose the vector variables the same unintuitive way. When choosing the dimensions of the vector you need to press (1) for 3 dimension, and (2) for 2. Again this is unintuitive. Because of this simple vector-calculations are faster if you do them in the normal mode. Note to manufacturer: In the next version of this calculator I would like to see fewer more intuitive menus, for example rather than pressing 3 buttons for the dot in vector mode it would be better to just use the decimal dot button instead. Rather than pressing 2 buttons to get the [vector], [matrix] etc menus there should be a special button which brings up the appropriate menu in each mode. The menu options should be easier to remember: eg to press 3 for a 3 dimensional vector, press the button with A over it (-) to get VctA in the vector menu. Also I would like better hardware. probably it would cost a fraction of a penny to be able store like 200 characters instead of 100.

Whilst the calculator has a negative side the overall feel of this calculator is that it is perfectly satisfactory. I shall start with the negative. I have owned a couple of casio calculators in the past and they have all been extremely well built and sturdy to use. This calculator is the first I have used which genuinely feels cheap, the buttons are tacky and make annoying sounds and rotate easily within their pits. However, I haven't had any trouble with breakages or buttons not registering my presses, it just seems shoddily built. On the plus side the calculator is easily adequate for most levels of mathematicians. I currently study AS maths and have found lots and lots of functions that I have never heard of, let alone need. The main reason for me buying this was the ability to integrate and differentiate to check my answers, as well as solve quadratic equations. On top of this the calculator can work with imaginary numbers, solve up to cubic equations, use matrices and lots of other niceties. For such a cheap price relative to the top end calculators I don't see the need to lash out on something which will break the bank, I can see this lasting at least up to early maths degree level if one chooses to take this route and for now I'm glad I decided to upgrade. Don't think twice about buying this (unless you feel the need to drop it from above a couple of metres, after which it is sure to break). Summary: Cons - cheap build quality Pros - lots of features which will be adequate for a large chunk of maths progression