Texas Instruments TI-15 User Manual

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Page 1

TIN15

Calculator and Arithmetic Trainer



1999 Texas Instruments Incorporated

General Information

The TI-15 has two power sources-battery and solar. It
operates in well-lit areas using solar cell, and it operates in
other light settings on battery.

Examples: See the Examples page for representative
problems and keystroke sequences that demonstrate many
of the TI-15’s functions and capabilities. Before starting
each problem set, reset the calculator by pressing

−

and

”

simultaneously to help ensure that your displays are

the same as those shown in the examples. In Problem
Solving Auto mode, however, displays will vary from those
shown, because these problems are random.

Basic Operations

To turn the TI-15 on, press

−

If the calculator is on, press

−

to turn it off.

APD™ (Automatic Power Down™) turns off the TI-15
automatically if no key is pressed for about 5 minutes.
Press

−

after APD to power up again; the display,

pending operations, settings, and memory are retained.

Display and Scrolling

The TI-15 has a two-line display; each line has room for 11
characters. Entries that do not fit on the first line wrap to
the second, and then scroll when the second line is filled.
Exception: When computing fractions, the TI-15 displays
only one line, which scrolls when a problem exceeds the
capacity of the line.

Entries can be up to 88 characters. Exceptions: In Stored
Operations, the limit is 44 characters. In ‹ Man mode,
entries do not wrap; entries cannot exceed 11 characters.

When a result exceeds the capacity of the screen, it is
displayed in scientific notation. However, if the result is
greater than 10^99 or less than 10^L99, you will get an
overflow error or underflow error, respectively.

Scroll with ", !, #, and $.

Press " and ! to scroll through entries or to move the
underscore within a menu list.

Press # and $ to scroll through history or, within a
menu, to move to the next level of menu lists.

Clearing, Correcting and Resetting

”

Deletes the character to the left of the
cursor. In fractions, clears from right
bottom to left top.

”

Clears display and error condition.
(Does not clear value from memory.)

Clears value from memory.

−

and

”

To reset, hold down

−

and

”

simultaneously for a few seconds and
release. MEM CLEARED displays.
This completely clears the calculator
and restores all default settings. You
can also reset using the Mode menu
(see below).

Display Indicators

Indicator

Definition

‹

Calculator is in Problem Solving mode.

Calculator is in Place Value mode.

Fix

Calculator is rounding results.

z has been pressed.

A value other than zero is in memory.

Op1, Op2

Stored operation function is active.

Auto

In calculator mode, Auto simplification of
fractions is active. In ‹, Problem Solving
function is in Auto mode.

Integer division function is active (appears
only when cursor is over the division sign).

n
d

Results of division will be displayed in
fraction format.

N
D

n
d

The fractional result can be simplified.

More entry history or menus are available.
Press # or $ to access.

An entry or menu extends beyond the
capacity of the screen. Press ! or " to
scroll.

Mode Setting Menus

‡ ¢ ‹ Œ

Key

Menu Choices Displayed

‡
‡$
‡$$
‡$$$

. n/d (Decimal or fraction display)
+1 ?

(Show or hide in Op)

OP1 OP2

(Clear stored Op)

N Y

(Select or reject Reset)

¢
¢$

U n/d n/d (Select format of fractions)
Man Auto (Simplification procedure)

‹‡

Auto Man

(Automatic or Manual)

‹‡$

1 2 3

(Level of difficulty)

‹‡$$
‹‡"®$

+ - Q P ?

(Type of operation)

11-. -1-

(Place Value function)

Press ! or " to underline a menu item. To select the
underlined item, press ®. To exit, press

‡

Order of Operations

The TI-15 uses the Equation Operating System (EOSé) to
evaluate expressions.

1st

Expressions inside parentheses.

2nd

Functions that need a ) and precede the argument.

3rd

Fractions.

4th

Exponentiation (^) and roots (‡).

5th

Negation (L).

6th

Multiplication, implied multiplication, division.

7th

Addition and subtraction.

8th

Conversions (U n/d/n/d, F/D, 4%).

9th

® completes all operations.

Basic Arithmetic

T U V W r « ®

q, h, i, j, k,
l, m, n, o, p

Enters numerals 0 through 9.

T, U, V, W

Adds, subtracts, multiplies, divides.

Inserts decimal point.

Enters a negative sign. (Does not
act as an operator.)

X, Y

Opens, closes a parenthetical
expression.

Completes all operations.

Integer Division

When you divide a positive whole number by a positive
whole number with £, the result is displayed in the form
Q r R, where Q is the quotient and R is the remainder.

If you use the result of integer division in a subsequent
calculation, the TI-15 uses only the quotient; the remainder
is dropped.

Fractions

¥ ¢ ¦ ¤ §

Press after entering a number to designate the
numerator of a fraction.

Press ¥ after entering a number to designate the
denominator of a fraction.

Both numerator and denominator must be integers. If you
enter a denominator greater than 1000, or if a calculation
yields a denominator greater than 1000, the TI-15 displays
results in decimal format.

You can input either the numerator or the denominator first.

separates the whole number from the fraction in a
mixed number.

¢ displays a menu that lets you specify how fraction
results are displayed.

U n/d (default) displays results as mixed numbers.

n/d displays results as simple (improper) fractions.

¢$ displays a menu that lets you specify the
simplification method.

Man (default) requires manual simplification of fractions.

Auto automatically reduces fraction results to lowest
terms.

N/D"n/d indicates that fraction results can be simplified.

¤ enables you to simplify a fraction manually.

§ displays the factor that was used to simplify a fraction
in your last manual simplification step. Press § again to
restore the fraction to the screen.

¦ converts a mixed number to an improper fraction or
an improper fraction to a mixed number.

Ÿ converts a fraction to a decimal, or converts a
decimal to a fraction, if possible.

If a problem contains both fractions and decimals, the
results are displayed in decimal format. However, if you
press ‡ and select n/d, the results of division will be
displayed in fraction format, when possible.

Percents

ª y

Press ª after a entering a value to calculate a percent.

Press y to convert a decimal or a fraction to a percent.

Roots and Powers

¨ ¬

¬ lets you obtain the square root of a number. After
entering the number, be sure to close the parentheses.

¨ raises a number to the power you specify.

, which is stored internally to 13

digits (3.141592653590). In some cases, results display
with symbolic

, and in other cases as a numeric value.

Memory

z |

After a calculation, press z® to store the displayed
result in memory. If memory already contains a value, the
new one will replace it. When memory contains a value
other than 0, M displays on the screen.

To recall the value from memory for use in a calculation,
press | once.

To clear memory, press ||.