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- Hour 9 -

Put the Calculator to Work

This book has done some work already with the calculator program by adding or removing that program to and from the Start menu. In case you are curious as to how to use this accessory application, this hour explains how to use the calculator. The calculator program performs both simple mathematical and advanced scientific calculations.

You will find the calculator program in the Accessories menu. (Of course, if you left the calculator on your Start menu, you don't have to hunt very far for it.) The calculator was around in previous versions of Windows. Windows 95 supplies updated versions of the calculator that take advantage of the new look and feel of Windows 95.

The calculator program exemplifies the desktop analogy that Windows 95 tries to emulate. After all, most desktops have a calculator, right? This hour teaches you how to use the electronic versions of a calculator. If you add more desktop tools, such as the Microsoft Outlook program that comes with Microsoft Office 97, you can supplement the calculator program with a calendar and note file as well.

The highlights of this hour include:

If you've used the Windows 3.1 calculator program, you'll see that very little has changed in the way you use the Windows 95 equivalent program.

JUST A MINUTE: The calculator program is one of several programs, including the Clipboard viewer, Notepad, and WordPad programs, that you'll find on the Windows 95 Accessories menu. Subsequent chapters explain how to use these additional programs.

3.1 Step Up If you upgraded from Windows 3.1 to Windows 95, you'll also find the Windows 3.1 Calendar and Cardfile programs on your Accessories menu.

Calculate with Success

Calculators have gotten smaller over the years. The early calculators were bulky and did no more than modern-day, solar-powered calculators. Windows 95 changes all that; when you use Windows 95, you go back to using a big desktop computer to do your math homework and checkbook organizing!

Seriously, the presence of a Windows 95 calculator program provides you with all kinds of computing benefits. Throughout a working day, you use your computer constantly, writing letters, printing bills, and building presentations. As you work, you often need to make a quick calculation and, if you're like this author, your calculator is probably covered up beneath papers stacked a foot high. Once you start the Windows 95 calculator, it is never farther away than the taskbar.

3.1 Step Up Windows 95 lets you run an almost unlimited number of programs at the same time. As you are probably painfully aware, Windows 3.1, although in theory was supposed to run many programs at once, ran into memory problems after you started just a handful of programs. After working in Windows 3.1 for any length of time, starting and stopping programs, your memory limits could even be exceeded by starting as few as two programs at the same time.

Windows 95 does have a memory limit, but that limit is a more practical limit than the capacity of Windows 3.1. You certainly cannot start 40 programs at the same time and expect to have plenty of memory for 40 more, but there's enough memory space for you to run the calculator in addition to your other day-to-day programs.

TIME SAVER: The calculator program actually contains two calculators, a standard calculator and a scientific calculator. Most people will need the standard calculator that provides all the common mathematical operations required for day-to-day business affairs. The scientific calculator contains additional operations, such as statistical and trigonometric operations. The default calculator that appears when you first start the calculator program is the standard calculator.

Tasks 9.1 and 9.2 walk you through the use of the Windows 95 calculators. Even if you've used other computer popup-windowed calculator programs, you should follow along with Task 9.1 to see how the Windows 95 calculator program works.


Task 9.1: Using the Standard Calculator

Step 1: Description
The Windows 95 standard calculator provides full-featured calculator functions. When you use the calculator program, you can sell your own desktop calculator at your next yard sale. Windows 95 even lets you copy and paste the calculator results directly into your own applications.

JUST A MINUTE: The basic usage of both the standard and scientific calculators is identical. Therefore, once you master this task you'll have already mastered much of the scientific calculator's operation.

Step 2: Action

1. Start the Windows 95 calculator. If you followed the tasks in previous hours, the calculator program may still be on your Start menu. If not, display the Start menu, select the Programs command, display the Accessories menu, and click on calculator to start it. The calculator that you will see appears in Figure 9.1. If you see a calculator window with many more buttons than the figure's, select View | Standard to work with the non-scientific calculator.


Figure 9.1. The Windows 95 calculator program goes beyond a pocket calculator.


CAUTION: The calculator program does not let you maximize the window or resize the window. You can only minimize the calculator program to a taskbar button. If you need to move the calculator window you can do that, too.
2. To steal from an old cliché, it doesn't take a rocket scientist to use the standard calculator. Obviously the Windows 95 calculator performs standard addition, subtraction, multiplication, and division. Table 9.1 lists all the math capabilities of the calculator and describes each.

JUST A MINUTE: All of the calculator operations produce running totals, meaning that you can continuously apply operations, such as addition to the running total in the calculator's display.

Table 9.1. The Windows 95 standard calculator operations.
Button Keyboard Operation Description
/ / divide Performs division
* Shift+* multiply Performs multiplication
- - minus Performs subtraction
+ Shift++ add Performs addition
sqrt Shift+@ square root Calculates the square root
% Shift+% percent Converts multiplication to their percentage products equivalent
1/x r reciprocal Calculates the reciprocal of values
= =, Enter equal Displays the result of the current operation
+/- F9 sign change Reverses the positive or negative sign of the displayed value
Back Backspace edits display Removes the last digit of the value you've entered into the calculator
CE Delete clears display Clears the display of its current number
C Esc clears total Completely erases the running total from the calculator's display
MC Ctrl+L clears memory Clears the calculator's stored memory value
MR Ctrl+R returns memory Recalls the value stored in memory and displays that value in the calculator's window
MS Ctrl+M stores memory Stores the displayed value in the calculator's memory
M+ Ctrl+P adds to memory Adds the displayed value to the calculator's memory

CAUTION: Be careful when using the calculator's keyboard equivalents. As you can see from Table 9.1, for instance, the C key does not clear the total (Esc does), even though C appears on the calculator's button to clear the total.
3. Click over the numbers 1, then 2, then 3. As you click, the numbers appear inside the display.

4. Click the multiplication sign (the asterisk).

5. Click the 2.

6. Click the equals sign, and the calculator displays the result of 246.

7. Click C to clear the display.

8. The mouse is great for many things, but the mouse will only slow you down when using the calculator. Turn on the Num Lock feature of your keyboard. Most keyboards have a Num Lock indicator light that lights up when Num Lock is turned on.

Repeat the previous operation by typing the number 123 on your keypad. Press the asterisk. Type 2 on the keypad. Press the equal sign. The result, 246, appears as expected. As you can see, the keyboard is a quicker way to enter numbers and math operators. Press the Esc key (the shortcut key that clears the display).

TIME SAVER: The Backspace key erases any character that you type incorrectly.
9. As Table 9.1 describes, the percent key produces a percentage only as a result of multiplication. Therefore, you can compute a percentage of a number by multiplying it by the percent figure. Suppose that you want to know how much 35 percent of 4000 is.

Type 4000 and then press the asterisk. Type 35 followed by the percent key (Shift+5 on the keyboard). The value 1400 appears, as shown in Figure 9.2. The result: 1400 is 35 percent of 4000. (The word of in a math problem is a sure sign that you must multiply by a percentage. Calculating 35 percent of 4000 implies that you need to multiply 4000 by 35 percent.)


Figure 9.2. The Windows 95 calculator makes calculating percentages simple.


10. Most of the calculator's operators are binary operators, which means they work on two values. The square root and the reciprocal keys work on single numbers. (These are known as unary operators.) Press Esc to clear the display and type 64. Click the square root key or press the Shift+@ key to see the square root of 64, which is 8. (8 times 8 is 64.)

With the 8 still showing (remember that the calculator makes running totals, which means your next operation can work on the values produced by the previous operation), press the reciprocal key. The reciprocal key contains an X, which represents the number in the display. Therefore, if 8 is showing, the reciprocal key produces the value 1/8 or .125. Often the reciprocal key is useful for calculating stock quote values. Stocks are often priced in 8ths or 16ths of dollars.

11. When you want to negate the number in the display, click the +/- key. Suppose that you want to subtract the display's current value, .125, from 6.875. Although you could clear the display and perform the subtraction, it's faster to negate the .125 by clicking the +/- key, thus producing --.125. Then press the plus sign, and then enter 6.875 and press the equal sign.

12. Some calculators have multiple memories. Unfortunately, the Windows 95 calculator has only a single memory. To store a value in the memory, click the MS key (or press Ctrl+M). Click MS now to store the display's value of 6.75.

TIME SAVER: The calculator displays a letter M above the four memory keys when you store a value in the memory.
13. Whenever you want the memory value back in the display, click MR. For now, click the C to clear the calculator's display, enter the number 10.25, and press the minus sign. Now click MR to display the memory value, 6.75, that you stored in the previous step. The memory store kept you from having to enter the 6.75 a second time. Press the equal sign to see the result.

If you want to store a running total, click the M+ button every time you want to add the display's value to the memory. Click MC when you want to erase the memory contents completely. The M goes away from the memory indicator box when you clear the memory.

14. When you want to switch over from your application to the calculator to perform a calculation, and then enter the result of that calculation elsewhere such as in your word processor, select Edit | Copy (Ctrl+C) to copy the value to the Clipboard. When you switch back to the other Windows 95 application, you'll be able to paste the value into that application. You can also reverse the process by copying (or cutting) values to the clipboard from another application and then pasting that value into the calculator's display with Edit | Paste (Ctrl+V), where you then can perform a math operation on the value.

Leave the calculator window open for the next task.


Step 3: Review
The standard calculator performs all the operations that most Windows 95 users will need most of the time. The interface is simple and allows the use of a mouse or keyboard to enter the values. Perhaps most people will find that the keypad offers the easiest interface to the calculator as long as the Num Lock key is active.


Task 9.2: Using the Scientific Calculator

Step 1: Description
The second Windows 95 calculator, the scientific calculator, supports many more advanced mathematical operations. Despite its added power, the scientific calculator operates almost identically to the standard calculator. The standard keys and memory are identical in both calculators.

Step 2: Action

1. To see the scientific calculator, select View | Scientific. Windows 95 displays the scientific calculator shown in Figure 9.3.


Figure 9.3. The Windows 95 scientific calculator provides advanced operations.

TIME SAVER: If you are using either calculator and, in the middle of a calculation, you decide that you want the functionality of the other calculator, you can switch views to the other calculator, and Windows 95 saves the value of the display when you see the next calculator.
Obviously, the scientific calculator offers more keys, operators, and indicators than does the standard calculator. Table 9.2 lists the additional operators and actions supported by the scientific calculator.

Table 9.2. The Windows 95 scientific calculator operations.
Button Keyboard Operation Description
Sta Ctrl+S statistics box Opens the statistics box
Ave Ctrl+A mean Computes the mean average of the values in the statistics box
Sum Ctrl+T sum or sum of squares Computes the sum of the values in the statistics box, the sum of the squares, if you select the Inv option first
s Ctrl+D std deviation Computes the standard deviation of the statistics with a population parameter of n--1 or a population parameter of n if you click Inv first (n is an abbreviation for the number of items in the series)
Dat Ins adds to statistics box Adds the displayed value to the statistics box F-Ev
scientific notation. Turns displayed decimal (base 10) numbers into their scientific notation equivalents and back again
dms m deg/min/sec Converts the display into degrees, minutes, and seconds as long as the displayed value is in degrees. If you need to convert the displayed value to degrees, click Inv first
sin s sine Computes the sine of the display
cos o cosine Computes the cosine of the display
tan t tangent Computes the tangent of the display
( shift+( parentheses Starts a new level of parentheses (25 levels are possible)
) shift+) parentheses Closes the previous level of parentheses
Exp x Scientific entry Lets you enter decimal numbers in scientific notation
x^y y x raised to a power Computes the value of x (the display) raised to the y power (the next value you enter)
x^3 shift+# cube Multiplies the display by itself three times
x^2 shift+@ square Multiplies the display by itself
ln n natural log Calculates the natural logarithm
log l factorial common log Calculates the common logarithm
n! shift+! Calculates the factorial of the displayed number
PI p PI Displays the value of the mathematical PI
Mod shift+% modulus Computes the integer remainder
Or shift+| bitwise OR Returns the bit-by-bit, OR operation of the integer value in the display
And shift+& bitwise AND Returns the bit-by-bit AND operation of the integer value in the display
Xor shift+^ bitwise XOR Returns the bit-by-bit XOR operation of the integer value in the display
Lsh shift+< left bit shift Shifts the bits of the integer value in the display (you can perform a right bit shift by clicking Inv first)
Not shift+~ bitwise invert Reverses the bits in the displayed integer value
Int ; integer conversion Converts the displayed value to an integer (truncates the fractional portion)
A - F A - F high hex values Lets you enter hexadecimal (base 16) values from 10 through 15
F-E v Scientific notation Turns scientific notation on and off
Hex F5 convert to hex Converts the display to a hexadecimal integer
Dec F6 convert to decimal Converts the display to a decimal integer
Oct F7 convert to octal Converts the display to an octal integer
Bin F8 convert to binary Converts the display to a binary integer
Inv i inverse function Inverts many of the operations
Hyp h hyperbolic Sets up the sine, cosine, and tangent for a one-time hyperbolic calculation
Deg F2 degrees Displays the result in degrees
Rad F3 radians Displays the result in radians
Grad F4 gradients Displays the result in gradients
Dword F2 32-bit word Displays full 32-bit values
Word F3 16-bit word Displays 16-bit values
Byte F4 8-bit word Displays 8-bit values


JUST A MINUTE: The keys Ave, Sum, s, and Dat work only if you click the Sta first.
2. Obviously, this hour is not going into each of these scientific operations. To explain their purpose would be teaching you advanced math and not Windows 95.

Actually, if you have a need for these operations you already understand their use. The only new interface that you need to master to use these advanced operations is the statistical interface. To compute a mean or standard deviation, you must work with several values at a time (a series). The Statistics Box contains the series of values as you enter them because the calculator's display shows only a single line at a time.
Make sure that the Dec option is chosen and click C to clear the display of any values that might be in the calculator. Enter the value of 15. Click Sta, and the calculator displays the statistics display. The box is empty right now, but you'll fill it up as you go. Click the Dat key to add the value of 15 to the Statistics Box and return to the calculator so you can enter more values.

3. Enter 45 and click Sta, and then Dat.

4. Enter 65 and click Sta, and then Dat.

5. Enter 20 and click Sta. Your screen should look like the one in Figure 9.4. The calculator has yet to add the 20 to the series list, but as soon as you press Dat (do so now) the calculator will add the 20 to the series. Sta simply shows the Statistics Box dialog box.


Figure 9.4. The Statistics Box keeps track of your series of values.


6. Click Sta and then Ave to see the average mean.

7. Click Sum to display the sum of the Statistics Box. You don't have to show the Statistics Box before clicking the four statistical buttons as long as you've entered a series of values.

8. Click Inv and then s to see the standard deviation with a population parameter of n-1.

JUST A MINUTE: Windows 95 adds vertical scroll bars to the statistics box if the box contains more than four values.

The Statistics Box
The Statistics Box contains four command buttons labeled RET, LOAD, CD, and CAD. The RET button returns you to the calculator's screen by minimizing the Statistics Box. The LOAD button sends the selected value from the series to the calculator's display. CD removes the selected value from the series. CAD removes all values from the series.

In addition, the calculator always displays the number in the current series (the value of n) at the bottom of the Statistics Box. If you already entered the value of 20, your screen shows n = 4.

8. Just for grins, why not try changing the base of a number. Clear the Statistics Box by pressing Sta and clicking CAD.

9. Click the calculator's C key to clear the display.

10. Enter the number 197.

11. Click the Hex option to see that the calculator changes the value to the hexadecimal number C5. (Hexadecimal numbers, or hex numbers for short, sometimes contain the letters A through F.)

12. Click the Oct option to see the calculator change the value to base 8.

13. Click the Bin option to see the calculator change the value to base 2 (base 2 numbers consist of 1s and 0s only). Figure 9.5 shows the calculator program displaying a binary result.


Figure 9.5. Binary values con-sist of 1s and 0s.


14. Click the Dec option to see the calculator change the value back once again to the familiar decimal (base 10) value of 197. If you understand all these bases, you're probably a computer pro.

JUST A MINUTE: C and C++ programmers will recognize the need for the bitwise operators. This book does not describe those operators.
  1. 15. Close the calculator's window.


Step 3: Review
The scientific calculator requires more mathematical knowledge to use. The calculator itself is not difficult to use, but understanding some of the math can be. To use the calculator fully, you must master the Statistics Box. The Statistics Box contains a series of values on which you can calculate statistical results.

Summary

This hour showed you one of the most useful accessory programs, the calculator program, along with its advantages over its real-world desktop equivalent. The calculator program attempts to be more available on your Windows 95 desktop than its physical counterparts are to your own desk. Windows 95 contains two versions of a calculator: a scientific calculator and a standard calculator that performs more common operations.

Workshop

Term Review

binary The base-2 numbering system.

binary operators Operators that work on two values such as the addition and subtraction operators.

decimal The base-10 numbering system.

hexadecimal The base-16 numbering system.

n The number of entries in a statistical series.

octal The base-8 numbering system.

running total The Windows 95 calculator operations, such as addition and subtraction, keep operating on the calculator's running display. For example, if the display contains the value 87 and you press the plus sign, and then press 5, the calculator adds the 5 to the 87 and produces the sum of 92. If you press the plus sign again and enter another value, the calculator adds that number to the 92 producing a continuous running total. The running total continues until you clear the display or close the calculator program.

scientific calculator A Windows 95 calculator that supports trigonometric, scientific, and number-conversion operations.

series A set of values on which you perform statistical operations.

standard calculator A Windows 95 calculator that performs common mathematical operations.

statistics box A box that holds your entered series of statistical values. (The calculator's display can hold only a single value at a time.)

unary operators Operators that work on single values such as square root.

Q&A

Q Why would I ever need the scientific calculator?
A If the standard calculator does not perform all the math you need, you must use the scientific calculator. Even many business applications, such as financial analysis, require the use of advanced mathematical, statistical, and trigonometric operations, such as the average, standard deviation, and the factorial.

TIME SAVER: If you like to go to Vegas you'll use the factorial key a lot when computing odds at games of chance also. See, math doesn't have to be boring!
Q What is the Statistics Box for?
A The Statistics Box holds more than one value, whereas the calculator's display can hold only a single value at a time. When you must compute statistical measurements based on a series of numbers, you'll need a place to store that series of numbers. The Statistics Box is such a place.

By using the Statistics Box's four command buttons, you'll be able to manage the values in the Statistics Box. Once you build a series of numbers in the Statistics Box, you can click the various statistical operations to make calculations based on the series.

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