**Getting the Most Out of Your Casio fx-911MS**
*BY MIKE PARCHIMOWICZ, MACINSIDERS CONTRIBUTOR*
A recent calculator thread has gotten me thinking: most people don't know how to use their calculator!

Almost exclusively, every time I've tutored or been asked for some assistance by a McMaster student, I suggest that they use a certain feature that they didn't even know was possible.

First, it should be noted that this is the

*only* calculator that most professors/courses will allow you to use on a test.

Why is this? Because if

*one* student has a hardcore $1200 calculator that can do calculus for them, then they have an unfair advantage. This is Mac's way of levelling the playing field.

**Picture:** (Make sure you purchase the right one! It is the only calculator that Titles Bookstore sells)

**What ***can't* my Casio FX-991ms do?
While there are many things it can't do, such as fly, cure cancer, or ensure a good grade, the one thing I wanted to point out is that it cannot graph functions. Other calculators, like the TI-84 have this capability, and I think it's worth mention.

**What are some things I can do on my Casio FX-991ms?**
**NOTE: **I will not be posting an exhaustive list here...if you're curious as to some of the really amazing things your calculator can do, when you purchase(d) it, you got a little white 'booklet' that can tell you how to do crazy things like working with matrices and limited derivative/integration, estimation support. These are obscure, and in my opinion (having done a lot of math), unnecessary. If you understand how to take a derivative/integrate you can probably do it quicker than learning how to use this function. Either way, it's in the white booklet thing if you're keen on learning.

So what am I going to explain?

**0) How do I clear all of my calculator's data?**
Press [SHIFT] then [MODE]. Make the appropriate selection. Pressing [3] will clear everything, and put you calculator exactly as it was when you bought it.

**1) ****IMPORTANT: Angle-Measure**
Your calculator, as many do, has three settings: Degrees, Radians and Gradians.

Degrees: A circle contains 360 degrees

Radians: A circle contains 2pi radians

Gradians: A circle contains 400 gradians.

__ENSURE__ you have your calculator set to the proper unit of measure because your answers can be completely thrown off if you don't. A common mistake is for people to leave the calculator in degrees when they should have radians.

*How do I change between them?:*
Press [MODE] 4 times, your calculator should display:

Press the appropriate number to select the correct measure.

**2) How do I input TT?**
Press [SHIFT] and then the [EXP] Button.

**3) How do I use Scientific Notation?**
In many science courses, such as chemistry, scientific notation and significant figures are of utmost importance. It is possible for your calculator to interpret, and display scientific notation.

a) When inputting numbers into your fx-991MS, the [EXP] button will produce a letter

**E**. This stands for "*10^"

So how do I input say, Avogadro's Number, 6.02*10^23 into the calculator?

Hit [6], then [.] then [0] [2] then [EXP], then [2], [3] and then [=]. Your display will display 6.02

**E**23.

b) In order to have your calculator display answers in scientific notation, press [MODE] 5 times. Your calculator will display:

Press [2]. It will show Sci 0~9? It is asking how many placeholder digits you would like. Press any number [0] through [9]. Try it out, and see what you're comfortable with...I generally use [0].

*To return your calculator to its normal function, press [MODE] once, then press [1] (to select COMP).*
**4) How do I solve systems of equations with my calculator?**
A system of equations is anything of the form:

a1x + b1y + c1z = d1

a2x + b2y + c2z = d2

a3x + b3y + c3z = d3

Press [MODE] 3 times. It will display:

Press [1]. The calculator will ask whether you wish to solve for 2 unknowns or 3. If your equation only has an x and a y, press 2, if it is a system of 3 equations, press 3.

You will then proceed to input the coefficients a1, b1, c1, d1 and a2, b2, c2, d2 as I labelled above. Press enter after entering each. You will then see a display saying "x=" and a number. Scroll down by pressing the down arrow, to see "y=" (and "z=" if applicable)

*To return your calculator to its normal function, press [MODE] once, then press [1] (to select COMP).*
**5) How do I solve polynomial equations with my calculator?**
A polynomial equation is an equation of the form ax^3 + bx^2 + cx + d = 0..specifically, your calculator can use the quadratic formula (which has no x^3 term), and even the cubic formula to solve polynomials of degree 2 and 3.

To use this feature, Press [MODE] 3 times. As above, it will display:

Press [1]. Then press the right arrow. The calculator will ask whether you wish to solve a degree 2 or degree 3 polynomial. Make the appropriate selection.

You will then be asked to input the coefficients, a,b,c and d if applicable. The calculator will solve for the 'zeroes' aka. the roots aka. the x-values for which the graph of your polynomial touches the x axis.

*To return your calculator to its normal function, press [MODE] once, then press [1] (to select COMP).*
**6) How do I use complex numbers?**
Any of the above functions can also be done with complex numbers. To input using complex numbers, Press [MODE] once. The calculator will show:

Press [2]. Now you can input the imaginary number, "i" by pressing the ENG button, find the argument (arg) using the [(] button, the modulus, or absolute value (abs) using [)], and the Complex Conjugate (Conjg) using the ['] button.

**7) How do I store numbers?**
Your calculator can hold up to 6 numbers, which can be very useful if you find yourself constantly inputting the same numbers...like say you found that 19.54829% of people are blond, and need to use that number frequently in your calculation. It's quite tedious to keep inputting the same number, so to store the number, you can proceed as follows:

a) STORAGE: Input your number (or do whatever calculations produce your number), and press [=]. Then Press [ALPHA], [(-)] (for instance) and a letter A will appear. Press [ALPHA] [CALC] and an equals sign, = will appear. Press [Ans], and press [=].

b) RETRIEVAL: Press [ALPHA] and then [(-)]. Again, an A will appear, except this time your A is a placeholder for whatever number you have inputted in step a. So keeping with my example above, if I input 2 * A, My calculator will input 39.09658 (which is 2 * 19.54829).

**8) How do I make use of the calculator's built in constants?**
On your calculator's back cover, you will see a whole slew of constants. Press [CONST] and make your selection. You can use this exactly as if you had entered the entire number. For example, for planck's constant, Press [CONST], [0], [6] and press [=]. There are loads of formulae involving

**h** so you may use this one a lot if you are in physics/chemistry.

*****Important note*** **You will always be asked to remove the back cover during tests and exams. This is because people often write 'cheat sheets' on them. So if you depend on this function, make sure you memorize the numbers of the important constants (or of course, their values)!

**9) How do I use the calculator's unit conversion function?**
Also on the back cover of your calculator are a series of unit conversions. Look for the appropriate one.

Example: Suppose I want to convert from inches to centimeters. If I want to see how many centimeters are in 5 inches, I simply do the following:

Press [5], [SHIFT], [CONST], [0],[1], [=].

I will then see that 5 inches = 12.7 cm.

*****Important note***** You will always be asked to remove the back cover during tests and exams. This is because people often write 'cheat sheets' on them. So if you depend on this function, make sure you memorize the numbers of the important conversions!

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If there are any requests for specific functions on your calculator, please post a comment or PM me and I'll try to add it. These basics are extremely important and can really make your life easy if you're in science or engineering courses.