TI-83 Plus Graphing Calculator Basic Skill # 00 Entering and Editing Numerical Calculations

Basic Operations… Notice that the keypad has 4 blue operation keys, and a blue [ENTER] key which works like an equal sign key. You normally press the [ENTER] key after entering your calculation.

Try This Example

Basic Operations… Notice that the keypad has 10 white keys with the digits from 0 to 9, plus a white decimal point key, and a white negative number sign key. You must use this key and not the subtraction key to indicate a negative number.

Try This Example

Basic Operations… Notice that the keypad has 2 black keys for parentheses or grouping, plus a black key for “squaring” a number, and a black key for indicating other exponents.

Try This Example ( + ) x2 3 8

Try This Example ( - ) ^ 2 6 3

Parentheses (or grouping) Exponents Order of Operations The calculator always performs operations according to the “universal” order: Parentheses (or grouping) Exponents Multiply or Divide from left to right Add or Subtract from left to right

Try This Example

Try This Example

Try This Example

Try This Example

Ooops... What if you make a mistake and type in the wrong calculation?

2nd KEY Notice that the keypad has one gold key labeled 2nd and there are words written in small gold letters above many of the other keys. The 2nd key works like the “Shift” key on a computer keyboard. To perform the functions or operations written in small gold letters, first press and release the 2nd key and then press the key below the gold command.

Correcting Mistakes… Notice that the gold command above the blue [ENTER] key is ENTRY. If you type in a calculation, press [ENTER], and then realize that you made a mistake, you can edit this previous entry by first pressing the gold 2nd function key and then the blue [ENTER] key.

Try This Example Ooops, 237 should have been 239!

To correct your mistake, press... 2nd ENTRY ENTER Then use your left arrow key to move the cursor over the entry you need to correct...

Recalculating the New Entry... With your cursor over the 7 in 237, type the correct digit and then press [ENTER] to recalculate your new entry. ENTER 9

Inserting more digits and/or operations... When editing an entry, the calculator normally only allows you to “replace” or “type over” an existing digit or operation. If you need to insert more digits or operations, you must put the calculator into “insert” mode. INSERT is the 2nd function command on the DELETE key.

Ooops, what if the 239 should have been 2039! Try This Example Ooops, what if the 239 should have been 2039!

To insert another digit, press... 2nd ENTRY ENTER Then use your left arrow key to move the cursor over the entry you need to correct (over the 9)...

2nd DEL INSERT mode... With your cursor over the 9 in 239, press... Notice that your cursor changes from a full rectangle to a small underline.

INSERT mode... ENTER Now type in the new digit... Then press [ENTER] to recalculate the new entry...

2nd ENTER Correcting Entries... ENTRY Pressing the 2nd function key and [ENTER] the first time will display the most recent entry and allow you to edit it. Pressing the 2nd function key and [ENTER] key again will display the second most recent entry and allow you to edit it. Pressing these keys again and again will continue displaying previous entries in the calculator’s memory.

What about fractions?? Will the calculator perform operations with fractions?

Entering Fractions... Notice that the keypad does not have a special “fraction” key so fractions must be entered as a division (numerator / denominator). A mixed number must be entered as a sum of the whole number plus the fraction. (whole number + numerator / denominator)

Try This Example Notice that the answer is displayed as a decimal, not a fraction! The calculator will always display answers in decimal form unless you use a special command to convert the decimal answer to fraction form.

Let’s edit this entry, press... 2nd ENTRY ENTER Now let’s use a special command to convert the answer into a fraction.

Press... MATH Then press... ENTER

Then press [ENTER] a second time to recalculate your entry... Notice that the answer is now displayed as an improper fraction!

MATH MATH OR ENTER 1 Anytime you enter fractions into a calculation and you want your answer expressed as a fraction, press [MATH] and then [ENTER] (or [MATH] and then the [ 1 ] key) before pressing [ENTER] to complete the calculation.

Summary Remember the special keys used for special numbers or operations negative number key parentheses keys (order of operations) x2 “squared” key or ^ “exponent” key 2nd function ENTRY command for correcting mistakes or editing previous entries “>Frac” command for converting answers into fraction form