Many times the tool we use will affect the result and the good one will not only give a better result but experience as well. One of the most common tools required by students is a calculator and those who will be taking higher-level math class will need something like Casio FX 115ES Plus Vs FX 991EX. These scientific calculators are very reliable but also slightly different in capabilities so before making a decision, go check what they can offer below first.

In this article, we are going to give you information about:

- Which Calculator to Purchase
- What Scientific Calculator is Used For
- What are Casio FX 115ES Plus and FX 991EX
- What Casio FX 115ES Plus and FX 991EX Look Like
- How are the Menu and Layout of Casio FX 115ES Plus and FX 991EX
- How to use Casio FX 115ES Plus and FX 991EX
- What are the Functions in Casio FX 115ES Plus and FX 991EX
- Casio FX 115ES Plus Vs FX 991EX

**Calculator Types**

Computers and smartphones may be everything today but in some applications, you will not be allowed to use them, such as in a learning process. The one we can still utilize in such conditions and many other activities is calculator but not all calculators will be useful in your classes because different subjects and focus will need different tools as well to assist the lesson. In general there are basic calculators, business or finance calculators, and scientific calculators which are usually the most expensive and most complicated to use.

Basic calculator will only have a common function that we are using everyday in many cases such as add, subtract, multiply, divide, percent, positive/negative function and in some models square root. It is easy to use and in fact most of us will be instantly familiar with how they work without much confusion. Business calculator or also commonly called a financial calculator is the one we use to deal with money related problems; here you can count the value of money or payment.

Many of them such as **HP 12C Vs 10bII** are mostly used by professionals or students taking accounting courses while the calculator itself can be either using RPN or algebraic system depending on the model. The last and probably more advanced is scientific calculator and as the name suggests, this is the one used when you are studying science, engineering or dealing with math problems due to their collection of functions such as exponents, log, LN, trig functions, and memory that are useful in the application.

**Using Scientific Calculator **

Using a scientific calculator is not an instant process because for a beginner, we have to learn on how the tool operates first that you can check out in their manual since different models vary slightly as well. After understanding how to enter, clear history, and changing their button functions or how to adjust the mode if available, now we can use the tool to solve various problems especially trigonometry that uses sine, cosine, tangent, inverses, and even their hyperbolic functions.

For those dealing with trigonometric values, we can change the calculation between degrees, radians, and grads while now we are also able to access pi and Euler’s constant, e. In addition we can find buttons with function to calculate exponents to the second, third, or any other power. If you are working with scientific numbers, there is this Exp button that will let you input scientific numbers while engineering problems usually use exponents, logs, and scientific numbers. All of them will require steps to calculate but with a calculator, what we need to do is only entering the correct input.

**About Casio FX 115ES Plus and FX 991EX**

If you are here then it means you will need a scientific calculator and with almost endless options out there, the shopping may not be going to be a short trip especially for those who want to get the best option out of their budget. Any scientific calculator will be able to work with scientific problems but we prefer those from well-known manufacturers just because they have better build quality and it is easier to find a solution in case we will be facing certain issues with the product later.

Both local and overseas companies have various leading models and the more people using the calculator, the easier to find a solution or learning materials. One of the best options when it comes to scientific calculators is the Japanese brand Casio because they are very good not only in quality but also the product reliability and performance. The price point itself is very much the same as similar models from other brands like TI or HP so students and parents don’t have to spend much to get the ideal calculator.

They sure have various scientific calculators but some stand out more than the rest and they are Casio FX 115ES Plus and FX 991EX. These models are the favorite of many users not without a reason because first, they are powerful and will deal with all basic needs that you will be using in such a tool but second, also reliable and easy to understand. What can get confusing is that they are also very similar to each other, making it hard to decide which model we should go after.

In comparison the FX 115ES is an older scientific calculator from Casio as this model has been around since 2011 and continues being one of the bestselling models even among others from different companies. In 2016, they launched a new calculator and this is the FX 991EX which is more like the upgrade version of its older brother so for those who have been using the former calculator will get everything in this one too yet with some improvement to make it even more reliable.

**Casio FX 115ES Plus and FX 991EX Design and Display**

Putting the Casio FX 115ES Plus and FX 991EX side by side you can instantly tell what has been improved in the newer model and we can say that this one indeed has a better screen quality, the display looks crisp and overall easy to look at but, what makes you still considering the former model is actually the number/font size because it is bigger in 115ES thus, some users especially those wearing glasses may prefer the older calculator.

In addition, somehow the new model has a reflective display, it bounces back light and can be quite annoying to work with at night with a table lamp near or above it. The build quality seems the same, the 991EX is lighter and may feel slightly flimsy on some hands including those who will be using the tool in the field. However, the keys or buttons are very similar, they are not the best but big enough to press quickly, responsive, but not too loud.

**Casio FX 115ES Plus and FX 991EX Menu and Layout**

The first thing we want to mention about the differences between these similar calculators is their menu because if you are familiar with the 115ES Plus, pressing the menu will send you to a list of options while the 991EX has a set of icons to select. Selecting the option is also a bit different as you will need to press the corresponding number of each stated on the list but in the latter you will need to press the equal button.

However, the button layout of these calculators are identical, you will find a certain button at the same place but now with a different shape. They still have these shift buttons and alpha buttons on the top left which should be pressed whenever you want to access the function stated in the same color.

**Solving Problem with Casio FX 115ES Plus and FX 991EX**

As the same type, these calculators will also work in the same manner and there are tons of functions here to try and use. For example let’s use the fraction function to solve a problem which is also going to use parenthesis. They are easy to use combined with the Math view making the problems appear the same to those we see in the book. Type a quadratic formula like 4+42-4(1)(2)2(1) use the arrow to navigate the box and when done, just press equal button then you will be shown the result which is 2+√2.

When you try with simpler problem such as 2145 then pressing the equal button, they will give you the same format that it simplified but, if you want the more useful form or decimal form depending on what the number will be used for, just press the S-D button and this will transform the result into decimal instantly.

**Casio FX 115ES Plus and FX 991EX Functions**

In general you can do what possible in the older model with the new calculator as well. Some noticeable differences first is somehow this U.S version is lacking LCM, GCD, Remainder division, Recurring decimals, and Product calculation. On the other hand, the older model can only handle two or three variables instead of up to 4 in the Equation mode. This model will also let you select the degree of Polynomial up to fourth compared to three which means you can do quadratic or cubic but 991EX will also let you do quartic.

**FX 115ES Plus vs FX 991EX**

These calculators are fairly the same and what makes them attractive is the price range in which they are also identical to each other. Performance wise the FX 991EX has better display and faster processor so it can give the result faster as well, including how it adds some useful upgrades for example in the equation mode but on the downside, it has smaller fonts and some functions that may be useful to you are missing.

Name | FX 115ES Plus | FX 991EX |
---|---|---|

Brand | Casio | Casio |

Features | - Natural textbook display shows expressions and results exactly as they appear in the textbook - Over 280 functions, including fractions, statistics, complex number calculations, base arithmetic, linear regression, standard deviation, computer science, and polar-rectangular conversions - Multi-replay function allows you to backtrack step-by-step through calculations, where you can edit expressions and recalculate answers - High Resolution Display to view more data like spreadsheets & 4x4 matrix calculations | - Natural Text book display - symbols and numbers appear just as they do in textbook - Numeric Integration/Differentiation. 552 functions - Simultaneous and Polynomial Solver - Solar Powered with Battery Backup (LR44 Button Cell Battery Included) |

Price | ||

Rating | 4.0 out of 4.5 stars | 4.4 out of 5.0 stars |

Best deal | Save Money Please click here | Save Money Please click here |

**Conclusion**

NOTE : Product prices, availability, ratings and save money information are accurate as of the date/time indicated on post time (as seen right bellow the post) and are subject to change. Any price, availability and save money information displayed on Amazon Site at the time of purchase will apply to the purchase of this product.

Overall you can go well with any of them because they are equally reliable but depending on what you will need to do later, it is better to base the option on your own preference and if you will not need those missing functions, FX 991EX is actually a very good upgrade.