Sign in to turn on 1-Click ordering.
More Buying Choices
Refresh Cartridges Add to Cart
15.20 + FREE UK delivery
9to5 Supplies (VAT receipt supplied) Add to Cart
14.53 + 2.16 UK delivery
16.90 + FREE UK delivery
Sorry, this item is not available in
Image not available for
Image not available


Casio FX-991ESPLUS Scientific Calculator

by Casio
4.7 out of 5 stars  See all reviews (206 customer reviews)
RRP: 27.99
Price: 15.98 & FREE Delivery in the UK. Details
You Save: 12.01 (43%)
o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o
In stock.
Dispatched from and sold by Amazon. Gift-wrap available.
Want it Saturday, 19 April? Choose Express delivery at checkout. Details
  • The Casio FX991ESPLUS is Casio’s most advanced scientific calculator with 417 mathematical functions
  • Recommended for Advanced GCSE, A/AS level and Highers
  • This ever popular model is now available with Random Integers and an improved equation mode
  • Solar Powered with Battery backup
  • The large Natural Textbook Display (Natural-V.P.A.M.) shows mathematical expressions like roots and fractions as they appear in your textbooks which increases comprehension because results are easier to understand
  • 3 year guarantee
See more product details

Frequently Bought Together

Casio FX-991ESPLUS Scientific Calculator + Helix Oracle Maths Set
Buy the selected items together

Product Information

Technical Details
Model NumberFX-991ESPLUS-SA-UH
Item Weight132 g
Material Typeplastic
Number of Items1
Manufacturer Part NumberFX-991ESPLUS-SA-UH
Additional Information
Best Sellers Rank 51 in Office Products (See top 100)
Shipping Weight259 g
Date First Available14 Jan 2010
 Would you like to give feedback on images?

Product Description

Product Description

The Casio FX991ESPLUS is Casio’s most advanced scientific calculator with 417 mathematical functions;Recommended for Advanced GCSE, A/AS level and Highers;This ever popular model is now available with Random Integers and an improved equation mode;Solar Powered with Battery backup;The large Natural Textbook Display (Natural-V.P.A.M.) shows mathematical expressions like roots and fractions as they appear in your textbooks which increases comprehension because results are easier to understand;3 year guarantee.

Manufacturer's Description

New CASIO Standard Scientific Calculators with Natural textbook display format!! CASIO's original "Natural Expression Input Display" and "Natural Expression Output Display" make it possible to display fractions, exponents, logarithms, powers, and square roots just as they are written in the textbook. The result is enhanced student comprehension and improved math class efficiency.The FX- 991ES PLUS has a matrix display and solving equations has never been easier as this is one of the new functions. Another is random Integers where you specify the range of random integers you want to generate and the FX991ESPLUS will display them. The number of memories has also been increase from 7 to 9. The FX991ESPLUS has many functions that can be use to solve many problems. Our users say they love the fact that the scientific calculator use two types of power, one solar and the other battery so is ECO friendly and you are safe to take it into an exam without it failing not to work. Others opinions of the product is that they think that it is one to the best calculator that you can buy. One of the advantages that we are told about is that the result that you get you able to use the same figure in the next part of the sum, without having to round up numbers or to re-type up the whole digits which can lead to errors. Other great functions that we are told about was that you are able to use the calucator to work back wards, such as in algebraic equations. This can make life so much easier or so our users tell us. The high technical specifications make this the most powereful Scientific at this price point.You can use this calculator from School to University and on into work.

Other Casio models to consider

If you require an even more powerful and more advanced calculator, the Casio Graphic calculator range provides dynamic graphing, capable of calculating and displaying graphs, charts, spreadsheets and statistics. The Casio Graphic range includes the FX-9750GII, FX-9860GII and FX-CG20

Why a Casio Calculator?

Casio is the UK’s No.1 calculator brand. Pioneering developments for over 50 years, since first inventing the electronic calculator in 1957, Casio are leaders in the development of calculator technologies and mathematical tools. Suitable for daily use, whether you are studying for mathematical qualifications, working on complex financial analysis, wanting time saving desktop assistance or looking for handy calculations whilst on the move. The Casio range of Graphical, Scientific, Desk and Pocket Calculators are powerful and rugged mathematical tools, built specifically for your task at hand.

Why a Casio Scientific/Graphic calculator?

Casio have pioneered the development of mathematical tools for over 50 years and have always provided devices embedded with ease of use, advanced features and progressive learning functionality. The Casio range of Scientific and Graphic calculators enhance mathematics study along with a broad range of associated subjects and assessments. The Casio educational calculator range provides a series of features and devices which will continue to develop student understanding, interpretation and fundamental knowledge of the subject area.

Technical Details

  • Natural Textbook Display
  • Two Way Power
  • 417 functions
  • Parentheses 24
  • Multi-replay
  • Reset
  • Degrees
  • Trigonometric (SIN/COS/TAN)
  • Radians
  • Gradians
  • Integration Differential
  • Equation calculation
  • Logarithm
  • Exponents
  • Reciprocals
  • Degrees/minutes/seconds
  • Exponential regression
  • Negative Indicator
  • Hyperbolics
  • Expression editing
  • Backspace/delete
  • Matrix calculations
  • Auto power off
  • Normal Distribution
  • Random numbers
  • Logarithmic regression
  • Power regression
  • Quadratic regression
  • Inverse regression
  • Linear regression
  • Coordinate conversion
  • Factorials
  • Roots and powers
  • Matrices
  • Equation Solver
  • Formula Solver
  • Numeric Differentiation
  • Numeric integration
  • Square root
  • DEC/HEX/BIN/OCT conversions
  • Vector calculations
  • Complex number calculation
  • CALC function
  • SOLVE function
  • Base-n calculations
  • Random Integers
  • Fraction calculation
  • Combination and Permutation
  • Logarithm log
  • List-based STAT data editor
  • Standard deviation
  • Paired-variable statistics regression analysis
  • Logical operations
  • Table function
  • 40 scientific constants
  • Metric / Imperial Conversions
  • 40 metric conversions (20 conversion pairs)
  • 9 variable memories
  • Comes with slide on hard case

  • Customer Questions & Answers

    Customer Reviews

    Most Helpful Customer Reviews
    112 of 115 people found the following review helpful
    5.0 out of 5 stars Ideal calculator from GCSE to PhD 9 Sep 2010
    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.
    Read more ›
    Was this review helpful to you?
    15 of 16 people found the following review helpful
    5.0 out of 5 stars Great Calculator - Though banned in certain unis 23 Oct 2011
    This is a great calculator.

    Loaded with functions, including arithmatic Integration and Differentiation (No algebraic though), solving equations, (Ie it can work out which values of x satisfy 3x^2 + 9x + 2 = 0)

    The display is also very good for laying out calculations and it has 40 scientific constants loaded into it's memory which are all noted on the back cover.


    I used this calculator for my A-Levels, took it to Uni then discovered that it's banned for all the examinations at my University! Make sure you check any calculator policies before you purchase.

    Main things to look out for are:

    Abiliy to solve equations

    If the policy notes any of these, you probably won't be able to use it. Check out the Casio FX-85GT if needs be.

    Otherwise a very handy calculator. (Also it's shiny)
    Comment | 
    Was this review helpful to you?
    15 of 16 people found the following review helpful
    5.0 out of 5 stars Great Product 19 Jun 2010
    This is the calculator that all people sitting A levels in maths and further maths should be using. With a simple easy to use panel that nobody could be confused by combined with limitless functions including both integration and differentiation. Does not get you your A level but gives you a massive boost. Especially for the A2 modules. Also has detailed functions for Vectors and Matrices. I cannot recommend this product enough!
    Comment | 
    Was this review helpful to you?
    3 of 3 people found the following review helpful
    5.0 out of 5 stars Best calculator 18 Jan 2013
    By Deasy
    Verified Purchase
    Its the best calculator i have owned (as far as calcs go anyway!). Great for my mech Eng degree and i never have to worry about the battery failing in an exam!
    Comment | 
    Was this review helpful to you?
    3 of 3 people found the following review helpful
    3.0 out of 5 stars Great calculator, poor build quality 10 Jan 2013
    Verified Purchase
    This is by far the best calculator I've used to date and it's packed with all the functions I will need for GCSE, A level and probably further. It's very easy to use and the screen displays everything in an easy-to-read manner, however:

    the calculator itself is made from a really cheap feeling plastic and is very light (93 grams without cover) compared to the likes of the FX-85GTPLUS, and it's quite a big let down. I'd rather pay 5-10 more for a calculator with similar build quality and weight to the FX-85GTPLUS with all the features of the FX-991ESPLUS.

    another problem with the calculator's cheap plastic shell is that without the cover on the back, the bottom left part isn't even, so when you press a key on the left side the calculator makes this horrible cheap plastic sound against the table.

    But again, the mathematic functions and ease of use of the calculator are amazing, just such a letdown on the build quality.
    Comment | 
    Was this review helpful to you?
    3 of 3 people found the following review helpful
    5.0 out of 5 stars Great 23 Feb 2012
    By Big T-S
    Verified Purchase
    Good calculator. Easy to use with lots of features, and never let me down whilst I was doing degree level science and mathematics.

    Top drawer!
    Comment | 
    Was this review helpful to you?
    2 of 2 people found the following review helpful
    5.0 out of 5 stars Best Scientific Calculator Out HANDS DOWN 2 Jan 2014
    By roro
    I bought this calculator during my gcse's without realising its full potential until doing my a-levels. I am now in my second year of a levels and this calculator has been an important tool during my first year (AS level) in studying Maths and Further Maths. The calculator allows you to check over your answers in exams especially for summation equations and integral equations. This aided me in getting 2 A's in Maths and Further Maths. This doesn't mean that you can revise less than your planning to, the calculator only assisted me in waisting less time in exams and safe guarding those vital marks lost by silly mistakes and rushing. If your not studying Maths at A level or higher than this calculator will only be as good as any other calculator on the market to you.
    Comment | 
    Was this review helpful to you?
    Most Recent Customer Reviews
    4.0 out of 5 stars Good, but not an HP.
    I bought it because it was one of the models accepted in certain examinations.

    But you will be disappointed if you are used to HP's RPN mode.
    Published 4 hours ago by MF Fernandes
    4.0 out of 5 stars Engineering Calculator
    Treated myself to this calculator for work, as an Engineer I use it every day. Needed to download the full manual to get the answer display as required. Great value for money.
    Published 16 days ago by S Flynn
    5.0 out of 5 stars Nice calculator!
    I love its pro features and portability and also the two way power. It is said two way power but I am not sure about this. Read more
    Published 18 days ago by prakash
    5.0 out of 5 stars Good calculator
    Really good calculator, easy to use comes with instruction manually if you can't figure out how to do certain equations. And cheap too
    Published 22 days ago by richard
    4.0 out of 5 stars manual lets product down
    comprehensive.manual print small and in some cases badley formed i need larger type and better instructions. what do you suggest.
    Published 25 days ago by fred gillett
    5.0 out of 5 stars BEST!
    Approved by the universities with 417 calculations and solar energy, at price nothing come close!The construction is very good ,i dont think anyone to expect Apple quality for 20... Read more
    Published 1 month ago by NIKOLAOS BARDAS
    5.0 out of 5 stars Perfect purchase
    The purchase was alright. This calculator is incredible! I suggest to everyone who needs a scientific calculator, it's definitely a good deal.
    Published 1 month ago by Daniel Cosovanu
    5.0 out of 5 stars good calculater
    a very good replacement for my old one which lasted a long time, I like the light aided power source
    Published 1 month ago by Graeme
    5.0 out of 5 stars :D
    Great for GCSE and AS/A2 Maths and Further maths if you dont want to buy the graphical calculator. Good Price Too!
    Published 1 month ago by Farhad
    5.0 out of 5 stars Saw me through an OU Astrophysics course
    if you need to enter calculation figures as n.nn.. times 10 to the power of n then this is the calculator you want. Read more
    Published 1 month ago by Amazon Customer
    Search Customer Reviews
    Only search this product's reviews

    Look for similar items by category