Graphing Calculator Keystroke Guide; Divide; Decimal - Texas Instruments TI-82 Keystroke Manual

TI-83 GRAPHING CALCULATOR
KEYSTROKE GUIDE
As you look at the pages in your textbook, you will notice that on some pages a book icon & appears
with a brief description of a feature on your TI-83 graphing calculator. In this guide the page number
in the textbook on which each of these book icons occurs is shown, as well as the key word or phrase
which appears next to the icon, followed by a detailed description of how to use this feature on your
TI-83. Each feature is also given its own number for easy reference.
page 3
1

Divide

The symbol ÷ appears on the division key of the TI-83, but on the screen division is indicated by
the diagonal slash /. Do the division 24 divided by 6 by pressing 24 ÷ 6 ENTER. Note that on the
Home screen the division appears as 24/6, which means the same thing, and the result is still 4.
Fractions may also be entered as divisions. For example, the fraction
3 divided by 4. You may enter the fraction that way on your calculator. On the screen you will see
3/4. When you press ENTER, you will see the decimal equivalent of .75. (See also 13 Fraction.)
page 4
2

Decimal

Press the MODE key. Notice that on the second line of mode settings the word Float is probably
highlighted. If not, move the blinking cursor over the word Float and press ENTER. Press 2nd
[QUIT] to return to the Home screen. Unless the computation comes out exactly using fewer digits,
when the calculator is set to Float mode, the calculator displays 10 digits, and the decimal point
occurs at its appropriate place in the 10-digit display. As a result, sometimes more digits are
displayed to the right of the decimal point on some computations than others. The decimal point
"floats" to wherever it should be in the 10-digit display for a given computation. For example,
perform the following three divisions: 17÷8, 368÷7, and 9543÷7. Since the computation of 17÷8
comes out exactly at the third decimal place, the calculator displays only the number of decimal
places needed to show the result: 2.125. The other two computations do not come out exactly, no
matter how many decimal places are used, so the calculator displays ten digits and locates the
decimal point where it should occur in the 10-digit display: 368÷7 = 52.57142857 and
9543÷7 = 1363.285714. Notice how in these last two computations the first displays ten digits
with eight of them to the right of the decimal point, while the last also displays ten digits but with
only six of them to the right of the decimal point.
3
may be interpreted as
4
31