Calculator Basics For
The Texas Instruments 83, 85/86, and 89/92/Voyage 200 Calculators - Part 2
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Home Screen |
The Home Screen is where most of your calculations will be done. You can always get to the home screen by pressing <QUIT>. |
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Contrast |
Sometimes the display on your calculator will be either too dark or too faint. You can adjust the contrast. On the TI-82, 83, 85, 86, touch the 2nd key and let go. Hold down on an up or down arrow to change the contrast. A number indicating the contrast level is shown in the upper right corner. On the TI-89/92/Voyage 200, hold the green diamond <¨> key and then the <-> or <+> key. |
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Minus Signs |
There are two different "minus" signs on your calculator. They are NOT interchangeable. The <-> key above the <+> key is for subtraction. The <(-)> key, next to the <.> key is for making a number negative. They look a lot alike on the screen so be sure to use the one you intend. |
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Order of Operations
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Keep in mind that your calculator is only a tool. It is not a substitute for thinking and learning. It will answer the question you ask, not the question you meant to ask. Order of operations is one place people run into trouble. Implied multiplication (putting a number next to a variable, like 2x) has higher priority than explicit multiplication (when you use the <x> command) on the TI-82/5. Check your manual or use parentheses when in doubt as to the order in which an expression will be evaluated. Parentheses are especially important in fractions when either the numerator or denominator is more than a single term. |
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Parentheses for
trigonometric functions to powers |
In trigonometry, we have the function sin x. Standard notation for (sin x)2 is to write sin2x. This does NOT work on your calculator. On the calculator you will need to type (sin x)2 or (sin (x))2. |
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Scientific Notation |
If you do a calculation and end up with an expression like 2.345 E 14, this is calculator notation for 2.345 x 1014. You can enter 2.345 x 1014 into your calculator in scientific notation using the "EE" command by typing 2.345 <2nd> < , > 14. |
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Mode |
On each calculator, you will see a <MODE> button near the top of the keypad. Pressing this button takes you to a series of options for how data will be input or displayed. The calculator's default settings are fine to start off. When we need to change them, we will do so. |
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Entry |
At times you will type complicated expressions and make a mistake or want to use the expression again. In order to edit a previously typed line, press <2nd> and <ENTER> (to obtain the command "ENTRY") and the last line you typed will reappear as the active command line. If you press <2nd> <ENTER> again, you will get the previous entry. Keep pressing <2nd> and <ENTER> to go back further. The number of steps back that are accessible depends on the complexity of the expressions. |
