Short Introduction to Using Your Casio 300W

Objectives: By the end of this lesson, you will be able to:

• Put your calculator in the best modes for solving a problem and displaying the result
• Use calculator keys for secondary purposes
• Move the cursor on your calculator
• Enter expressions
• Solve an equation with multiple operations all at once
• Work with negative numbers

You will be absolutely amazed at how much work this calculator will save you. It probably cost you less than \$20.00 and it will save you hours, no days, of work.

 Important Note: Never push two buttons at the same time. Push one button, let it go, then press the next button.

Please have your calculator with you as you work through this lesson. If you look at the top row of buttons on your calculator, you will see that it has six buttons.

[SHIFT]   [ALPHA]   [<REPLAY]  [REPLAY>]   [MODE]   [ON]

Modes:

Press the [ON] button. (If you have long finger nails, click here)

Press [MODE] once and you should see:

You calculator is always in one of these modes (Comp, SD, or Reg).

Press [MODE] a second time and you should see:

You calculator is also always in one of these modes (Deg, Rad, or Gra).

Press [MODE] a third time and you should see:

You calculator is always in one of these modes (Fix, Sci, or Norm).

So, at any given moment, your calculator is in three different modes, one from menu one, one from menu two, and one from menu three (no substitutions allowed). If you press [MODE] a fourth time you go back to the original screen. What your calculator does depends, in part, on which combination of modes it is in at that moment.

Let's take a look at what each selection in Menu one does:

• "Comp" is the computational mode and is used for general calculations such as addition, subtraction, division, and multiplication. To select "Comp" from the first menu, you press 1.
• "SD" is the standard deviation mode and is used for single-variable statistics to calculate the mean, standard deviation, and variance. To select "SD" from the first menu, you press 2.
Press [ON]
Press [MODE]
Press [2]
You should see a very small SD near the middle bottom of the screen. If you are my age, get out the bi-focals.
• "REG" is the regression mode and is used for two-variable statistics to calculate the mean, standard deviation, and variance. To select "REG" from the first menu, you press 3. We will not use the "REG" mode until module 3 but then you will be soooo happy to have this mode.
Press [ON]
Press [MODE]
Press [3]
Press [1] (we will only do linear regressions, never log or exponential (but it is nice to know we could if we wanted)
You should see a very small REG near the middle bottom of the screen - just above the [REPLAY] buttons.
Press [ON]
Press [MODE]
Press [1]
The only way you know you are in "COMP" mode is that there is neither the SD or the REG showing on the screen.

The choices on the second menu are degrees, radians, or grads. When your calculator is on, there is a small black square is on the bottom of your screen, just above and to the left of the [MODE] button. The black square has a white D, R, or G in it telling you which of these modes is active. However, it is too darn hard to read and since these modes are only used for trigonometry, which we don't do in this course, we will move on to the next menu. For this class, it does not matter whether your calculator is in Deg, Rad, or Gra.

• Fix rounds for you.
Press [ON] no need to do this if your calculator is already on
Press [2]
Press the [÷] button (the button just below the red [AC] button)
Press [3]
Press [=]
Your display probably reads 0.666666666 (if not, don't worry - it will shortly)
Press [MODE]
Press [MODE] a second time
Press [MODE] a third time
Press [1] now we need to tell it how many decimal places to round
Press [2]
Also, notice that just to the right of that little black square from the second menu is the word "Fix."
• Norm is the normal display.
Press [MODE] (I am assuming that your calculator is already on. If not, turn it on.)
Press [MODE] a second time
Press [MODE] a third time
Press [3] you are then asked to select 1 or 2
Press [2] just take my word for this select 2 instead of 1 here
Also, notice that the word "Fix" is no longer to the right of that little black square. That is how you know you in normal display, by the absence of "Fix" and "Sci."
Press [7]
Press [4]
Press [1]
Press [0]
Press [.]
Press [2]
Press [5]
Press [8]
Press [×] the times sign, just under the red [DEL] button
Press [1]
Press [=]
Press [MODE]
Press [MODE] a second time
Press [MODE] a third time
Press [2] now it ask you how many digits you want to see
this is just 7410 written in scientific notation.
Note that there is now a small "Sci" at the bottom of the screen.
We won't use scientific notation in this class. I just want you to know how to recognize scientific notation when you see it. If somehow your kids (or grandkids) have been playing with the calculator and now you are getting these funny looking answers, you now know to put the calculator back into normal display mode. One caution, however, your calculator only has room on its display for 10 digits. Numbers bigger than this (or numbers with lots of decimal places) are automatically put into scientific notation regardless of your display setting. I don't think we will be encountering such numbers in this class. If we do, I'll warn you at that time.

[SHIFT] [] [<REPLAY] [REPLAY>] [MODE] [ON]

Shift and Alpha:

So far, we have only talked about two buttons on that top row of buttons, [ON] and [MODE]. Let's get to the others. Notice that the word "SHIFT" is written in yellow on your calculator and the word "ALPHA" is written in red. Now look at all the buttons below the first line. Notice how they all have something in white written on the key. If you just press that key, it does what is written in white. For example, if we were to press [sin] [.] [8] [5] [=] we would get 0.013351372, which is the sin of 0.85. However, look at the [sin] button real closely. Do you notice that the [sin] button has a small yellow sin-1 written above it (but below the [X2] key? If one were to press the yellow [SHIFT] key before pressing [sin] you would not get the sin you would get what is written in yellow above the [sin] key, which is sin-1 or the reciprocal of the sin. Did you also notice that there was also a red D written above the [sin] key? If you were to press [ALPHA] [sin], you would not get the sin, you would get D - what was written in red.

Cursors:

That leaves just the two replay buttons to explain. These are your cursor control buttons.

Press [1] [2] [3] [4] [5]
Your screen should say: 12345 with a blinking cursor after the 5.
Now imagine you decide that you didn't mean 12345, you meant 12945. We can change the 3 into a 9.
Press [<REPLAY]
Press [<REPLAY] a second time
Press [<REPLAY] a third time.
Now the cursor is under the 3
Press [9]
Press [REPLAY>]
Press [REPLAY>] a second time
Press [REPLAY>] a third time to get back to the right of 5.
Now, imagine, we decide we don't want 12945, we really want 1245. How do we get rid of the 9?
Press [<REPLAY]
Press [<REPLAY] a second time
Press [<REPLAY] a third time.
Now the cursor is under the 9
Press [DEL]
Press [REPLAY>]
Press [REPLAY>] a second time and we are back to the right of 5 and our display shows 1245. But we change our mind again. We really want 12845.
Press [<REPLAY]
Press [<REPLAY] a second time
Now the cursor is under the 4
Press [SHIFT] [DEL] [8]
Press [REPLAY>]
Press [REPLAY>] a second time To get back to the right of 5.

Now, let's try one more thing with our cursor.
Press [AC] to clear the screen

Press [5] [6] [×] [9] [8] [=]
Now you decide you didn't want to multiply, you meant to divide
Press [< REPLAY] repeatedly until your cursor is under the ×, then press [÷]
Press [REPLAY>] repeatedly until your cursor is at the end of the line
Press [=]
Now your calculator will say 0.571428571.

Entering Expressions:

Calculators have improved a great deal over the years. It used to be that if you wanted the square root of 9, you would press 9 then the square root button. Now if you want to know what the square root of 9 equals you press the buttons in the same order as you would say or write it. You would press the square root button then the 9 button then the equal button.

Also, on older calculators you would solve a complicated problem by solving a number of sub-steps then put them all together. For example, to solve 3 × 53 + 24 × 26 = , on an older calculator you would first find that 53 = 125, then you would multiply that by 3 to get 375. This number you would write down or put into memory. Then you would work the other half of the problem 26 = 64, and 64 times 24 is 1536. You would then add the 375 to the 1536 and you would get 1911.

On newer calculators like yours, you just type in the entire problem and solve it all at once: [3] [×] [5] [Xy] [3] [+] [2] [4] [×] [2] [Xy] [6] [=]

You get the same answer, 1911 (the year I was born). What you typed in remains in the upper half of the display screen. You can review it by moving the cursor keys. Your new calculator uses the same order of operations that you just read in your textbook. Sometimes, it helps to add parenthesis. For example. If you wanted to solve it helps to put parentheses around the numerator . Otherwise, you might accidentally be solving the equation

Practice Opportunities:

Let's try a few examples:

Solve Check answer by clicking here

Solve Check answer by clicking here

Negative Numbers:

It is important not to confuse the negative button [(–)] (which is just above the [STO] button) with the subtraction button [] (which is just above the [=] button). If you want to multiply 3 by –5, press [3] [X] [(–)] [5] [=]. Using the subtraction button instead of the negative button is very insidious. It will sometimes work and at other times it will give you a totally wrong answer (especially when we get to Module 3).

Squaring a Negative Number:

Hopefully you know that a negative times a negative is a positive. You also know that if you square a negative number you get a positive number. However, on scientific calculators (whether a Casio, Sharp, or Texas Instruments) if you enter a negative number (or have a negative answer) and then square it, you will get a negative. Let's try it. Let's square a negative two. [(–)] [2] [X2] [=]. See, you get –4, not +4. Your calculator is treating this as –(22) while you really want (–2)2. You will get the answer you want by pressing [( ] [(–)] [2] [ )] [X2] [=] and you will get a positive 4.

That is it for the calculator until we get into statistics.

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