Display Indicators

Indicator

Fix 4M M Op1, Op2 Auto

Integer Division
Calculator and Arithmetic Trainer
Copyright 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-15s 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.

n P d N n " D d

Definition Calculator is in Problem Solving mode. Calculator is in Place Value mode. Calculator is rounding results. z has been pressed. A value other than zero is in memory. Stored operation function is active. 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). Results of division will be displayed in fraction format. 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.
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

! "

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.

Mode Setting Menus

Key $ $$ $$$

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.

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) 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 (EOS) 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.
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. 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

Press after a entering a value to calculate a percent. Press y to convert a decimal or a fraction to a percent.
Clearing, Correcting and Resetting

Roots and Powers

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. 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).

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.

Basic Arithmetic

q, h, i, j, k, l, m, n, o, p T, U, V, W r M X, Y
Enters numerals 0 through 9. Adds, subtracts, multiplies, divides. Inserts decimal point. Enters a negative sign. (Does not act as an operator.) Opens, closes a parenthetical expression. Completes all operations.
enters the value of p , which is stored internally to 13 digits (3.141592653590). In some cases, results display with symbolic p , and in other cases as a numeric value.

Memory

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 ||.

US 15RG1L1A

Page 1

Stored Operations

Problem Solving

(continued)

Error Conditions
Arith Error Syn Error P0 Error Mem Error Op Error Overflow Error Underflow Error Arithmetical error. Syntax error. Attempting to divide by zero. Error in attempting to store entry in memory. Error following steps for using Op1 or Op2. Overflow. Underflow.
Op1 and Op2 each can store an operation with a constant value, which you can repeat by pressing only one key, as many times as desired. 1. Press or. 2. Enter the operator first (+, -, Q, P, IntP, or ^) and then the number. 3. Press or. 4. Initialize with a starting value. 5. Each subsequent time you press or , the operation with the constant is applied. The computation with the stored operation appears on the first line of the display, and the result appears on the second line. If you dont want the computation line to display, press $" to hide it. Or, if the expression does not fit on the line, it will not show. When space permits, a counter on the second line shows how many times you have pressed or. To clear the contents of Op1 or Op2, press $$, select Op1 or Op2, and press. Then press to return to the last result display.

Rounding

You can round results with in conjunction with place value keys to specify a given number of places. (The internally stored value is not rounded.) The calculated value is padded with zeros as needed. You must press again each time you change the number of places. Keys
When you first enter and when you press , the display shows the Scoreboard for a moment before presenting problems or before showing the menu. In Man (manual) mode, you compose your own problems. While in , press to access the menu list, and press " to select Man. Then press , and the TI-15 is ready for you to enter your problem and your solution. It accepts only non-negative integers in this mode. You indicate a missing element with. In Man mode, it is possible to enter a problem that has one solution, multiple solutions, or no solution. The TI-15 tells you how many solutions the problem has. Problems with one missing element generally have only one solution. You get three tries. After three incorrect answers, the calculator displays the correct answer and then clears so you can enter a new problem. Problems with two missing elements have multiple solutions. For example, ?+?=5 has 6 solutions; ?x?=24 has 8 solutions. (In this type of problem, the question marks replace the operands; they may not appear in the place of the operator or the answer.) These problems are not cleared after a correct solution or after three incorrect answers; the problem remains so you can enter other solution sets, until you clear the problem manually by pressing. When the answer to a problem is not a positive integer (such as 9P2), the TI-15 indicates that it has zero solutions. But if you enter answers, it will tell whether they are greater than or less than the correct answer. Inequalities. Instead of entering an equation, you can test an inequality using. You get only one try, because the inequality statement is either true or false. With inequalities you can enter decimals. Press once for <, and press twice for >. To exit Problem Solving, press again.
In some cases, restores the last display before the error message appeared. Errors appear in history as Error.

Battery Replacement

Place protective cover over the TI-15 and lay the calculator face down. Remove screws from back of case, using a small Phillips screwdriver. Carefully separate front from back, starting from the bottom. Caution: Be careful not to damage any internal parts. Remove old battery, using a small Phillips screwdriver, if necessary. Replace with new battery. Replace back of case. Caution: Avoid contact with other TI-15 components while changing the battery. If necessary, press and at the same time to reset the TI-15 (clears memory and all settings). Caution: Dispose of old batteries properly. Do not incinerate batteries or leave where a child can find them.

Action Rounds in thousands. Rounds in hundreds. Rounds in tens. Rounds in ones. Rounds to nearest tenth. Rounds to nearest hundredth. Rounds to nearest thousandth. Removes fixed-decimal setting.

Place Value

While in , Man mode, you can determine the place value of a digit; determine how many ones, tens, hundreds, thousands, tenths, hundredths and thousandths a number contains; or determine which digit of a given number is in a specified place. Determine Place Value: L After entering a number, you can determine the whole number place or the decimal place of a given digit by pressing and then pressing the digit in question. L If you have a number with a repeated digit, when you press this digit the TI-15 analyzes its right-most occurrence. To find the place value of those to the left, press the given digit again before the answer appears. Each time you press the given digit in succession, the display shifts to the next occurrence of this digit to the left and shows the place value for this occurrence. While in , Man mode, you can access a Place Value menu by pressing $. Find out how many ones, tens, hundreds, thousands, tenths, hundredths, or thousandths a number contains (default): If necessary, press "$, select the 11- setting, and press. Enter the number to be analyzed, press , and then press , , , , , , or. Find out what digit of a number is in a specified place: Press "$, select the -1- setting, and press. Enter the number to be analyzed, press , and then press , , , , , , or. The answer appears briefly and then clears so you can press another digit or place value key. Once the function is active, it is not necessary to press this key before each digit or place you wish to examine for a given number. You need to press before entering a new number to analyze and then activate again. To exit the feature, press.

In Case of Difficulty

Review instructions to be certain calculations were performed correctly. Press and simultaneously. This clears all memory and settings. Check the battery to ensure that it is fresh and properly installed. Change the battery when: does not turn the unit on, or The screen goes blank, or You get unexpected results. To continue using the TI-15 until you can change the battery: 1. Expose the solar panel to brighter light. 2. Press and simultaneously to reset the calculator.
These place-value keys also work with (see below).

The function lets you practice and test your skills in arithmetic. You can choose either Auto or Man mode. In Auto mode (default), the TI-15 presents problems with one element missing (for example, 5+2=? or 5+?=7 or 5?2=7). You can select the type of problem and choose from three levels of difficulty. The default is addition at level 1. Level of Difficulty. While in , press $ to access the menu list and press " or ! to select the desired level of difficulty (1, 2, or 3). Then press , and the TI15 will present problems at the selected level. Type of Problem. While in , press $$ to access the menu list, and press " or ! to select the desired type of problem (addition, subtraction, multiplication, division, or find the operator). Then press , and the TI-15 will present problems of the selected type. 1. You enter an answer. 2. If your answer is correct, the display shows Yes, clears the screen, and presents another problem. 3. If your answer is not correct, the display shows No and indicates whether the correct solution is less than or greater than the answer that you entered. 4. The incorrect answer is cleared from the display, and you enter another answer to that same problem. 5. If you enter three incorrect answers to a given problem, the TI-15 shows the correct answer, clears that problem, and presents a new problem. Scoreboard. The TI-15 shows a Scoreboard after every fifth problem. Every correct solution you have entered registers a Yes in the Scoreboard, and three incorrect answers in a row register one No. After 100, the Scoreboard returns to zero.
TI Product Service and Warranty Information

Product Support

Customers in the U.S., Canada, Puerto Rico, and the Virgin Islands
For general questions, contact Texas Instruments Customer Support: phone: e-mail: 1.800.TI.CARES (1.800.842.2737) ti-cares@ti.com
For technical questions, call the Programming Assistance Group of Customer Support: phone: 1.972.917.8324
Customers outside the U.S., Canada, Puerto Rico, and the Virgin Islands
Contact TI by e-mail or visit the TI calculator home page on the World Wide Web. e-mail: Internet: ti-cares@ti.com www.ti.com/calc

Page 2

TI Product Service and Warranty Information (continued)

Product Service

Customers in the U.S. and Canada Only
Always contact Texas Instruments Customer Support before returning a product for service.

T U V W ! " # $

3V4T2 3Q4+2= 14

3VX4T2YQ

3Q(4+2)=
Customers outside the U.S. and Canada
Refer to the leaflet enclosed with this product or contact your local Texas Instruments retailer/distributor.

94 9P4=

Other TI Products and Services
Visit the TI calculator home page on the World Wide Web. www.ti.com/calc

8 !!! 934=

Warranty Information
One-Year Limited Warranty for Electronic Product This Texas Instruments (TI) electronic product warranty extends only to the original purchaser and user of the product. Warranty Duration. This TI electronic product is warranted to the original purchaser for a period of one (1) year from the original purchase date. Warranty Coverage. This TI electronic product is warranted against defective materials and construction. THIS WARRANTY IS VOID IF THE PRODUCT HAS BEEN DAMAGED BY ACCIDENT OR UNREASONABLE USE, NEGLECT, IMPROPER SERVICE, OR OTHER CAUSES NOT ARISING OUT OF DEFECTS IN MATERIALS OR CONSTRUCTION. Warranty Disclaimers. ANY IMPLIED WARRANTIES ARISING OUT OF THIS SALE, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE LIMITED IN DURATION TO THE ABOVE ONE-YEAR PERIOD. TEXAS INSTRUMENTS SHALL NOT BE LIABLE FOR LOSS OF USE OF THE PRODUCT OR OTHER INCIDENTAL OR CONSEQUENTIAL COSTS, EXPENSES, OR DAMAGES INCURRED BY THE CONSUMER OR ANY OTHER USER. Some states/provinces do not allow the exclusion or limitation of implied warranties or consequential damages, so the above limitations or exclusions may not apply to you. Legal Remedies. This warranty gives you specific legal rights, and you may also have other rights that vary from state to state or province to province. Warranty Performance. During the above one (1) year warranty period, your defective product will be either repaired or replaced with a reconditioned model of an equivalent quality (at TIs option) when the product is returned, postage prepaid, to Texas Instruments Service Facility. The warranty of the repaired or replacement unit will continue for the warranty of the original unit or six (6) months, whichever is longer. Other than the postage requirement, no charge will be made for such repair and/or replacement. TI strongly recommends that you insure the product for value prior to mailing. Software. Software is licensed, not sold. TI and its licensors do not warrant that the software will be free from errors or meet your specific requirements. All software is provided AS IS. Copyright. The software and any documentation supplied with this product are protected by copyright.

2+3= 7N4= 7N4= 2Q4= 74N42= 32 2 3518T

"

+1 = 18 18

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9W33 9P9 4S

3 9P3= 3

" U n/d n/d

9P9P3= 3 318T4 9Q2= 18

N D n d

8W3!!w9

36 4S4 8

9W3wwV2

r 6r3T2r4 6.3+2.4= 8.7

All Customers Outside the U.S. and Canada
For information about the length and terms of the warranty, refer to your package and/or to the warranty statement enclosed with this product, or contact your local Texas Instruments retailer/distributor.

4r2V3r1

4.5 4.2Q3.1= 13.02

200V7 200Q7%= 14

96r3W2r52

96.3P2.52= 38.21428571 y

M 5TM2 5+ -2= 3

.3754%

2 4% 5

5N -2=

4Q -2=

Page 3

25Y 52 (25)= 5 25

8+3=? 3

8+3=11 Yes

8^13= 5.498Q10^11

V3 pQ3= 3p

12+5 3

Op1 Op2

3+5=8 Yes

9+7=? 15 6

Op1 Op2 Auto

V42 pQ4^2= 2T3V 2+3Qp= 11.42477796 96+85=

3Q6Q2 2

9+7>15 No

9+7<18 No

96TClear Op 90.5

12+5 1

9+7<17 No

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181P2=

OP 1 OP 2 CLEAR

9+7=16 Yes

4+?=6 3

98+87=
42r394V97r 382 4128.412508

4+2=6 Yes

185P2=

92.5 4000

92.5+90.5= 183

8+5=13 Yes

183P2=

91.5 4130

3 4128

4128.4

4128.41

4128.413

4128.412508

Page 4

3 $"

"

6+400=? 3

6+400=406 Yes

4379r652

4379.652 3

+ - Q P ? $$""

+ N Q P ?

4379.652 3.

10Q40=? 3

4379.652 3"100 5

10Q40=400 Yes

$ $ ! Auto 70N40=? 3 20

4379.652. 5

4379.652 5"0.01

70N40>20 No

7653.498 3

70N40=30 Yes

7653.498 7.

Man $"

7653.498 765349.

14N?=sol

14N4=10 Yes

7653.498 5.

?Q?=sol

7653.498.4

8Q3=24 Yes

?Q?=24 3

Copyright 1999 Texas Instruments Incorporated Texas Instruments 7800 Banner Dr. Dallas, TX 75251 U.S.A.

7Q6<43 Yes

15P3>4 Yes

www.ti.com/calc

Texas Instruments Holland B.V. Rutherfordweg CG Utrecht - The Netherlands

Page 5

Concepts/Skills
Fractions Proportional reasoning Problem solving

Activity 8

Materials
TI-15 Student Activity pages (pp. 54 - 56) Chart paper Markers Using the TI-15 (p. 57)

Thrift Store Markdowns

Overview
Students will calculate a series of discounts using increasing unit fractions.
Describe the following scenario to the students. A storeowner is interested in getting rid of some merchandise. He decides to discount the price by $1 each week. For example, a shirt that sells for $15.00 will be marked down to $14.00 the first week, $13.00 the second week, and so on. If he continues in this way, when will he give the shirt away? Have the students work through the problem. Ask the students to come up with an alternative since the storeowner does not really want to give merchandise away.

First Things First

For students not ready for the open-ended problem, start with the First Things First activity page.

Presenting the Problem

Have students read the Thrift Store Markdowns activity page. Make sure they understand the final product and the required presentation.
2002 TEXAS INSTRUMENTS INCORPORATED
Activity 8: Thrift Store Markdowns

Evaluating the Results

Have students share the charts they created. Have them determine if the calculations used are the same or different. Discuss the similarities and differences between the charts and the calculation methods. Have students evaluate how the TI-15 helped solve this problem
_________________________ _________________________

Student Activity

Thrift Store Markdowns: First Things First

The Problem

After shopping for hours, you find the same shirt at two different stores. In store #1, the original price is $24.00 and it is marked 1 off. In store #2, the 3 original price is $20.00 and it is marked 1 off. Where should you buy the 5 shirt? On the same shopping expedition you find jeans at two different stores. At the first store, the original price of the jeans is $34.00 and they are marked down 1. At the second store, the original price of the jeans is $37.00 and they 4 are marked down 1. Where should you buy the jeans? 3

Working the Problem

One way to calculate the price is to use parentheses. 1. Enter 24 U X 24 V Y. This gives the price at the first store. What is the price? How much do you save at store #1? 2. Enter 20 U X 20 V Y. This gives the price at the second store. What is the price? How many dollars do you save at store #2? 3. Where should you buy the shirt? 4. Now look at the prices for the jeans in the two stores. How will you set up the TI-15 for these prices?
Calculate the sale prices at the two stores. Store #1: Store #2: 5. Where should you buy the jeans?
The Problem: How many weeks of markdowns will it take for the furniture at the thrift store to be half price?
Mrs. Nguyen, the manager of the local hospitals thrift store, discounts furniture by increasing amounts each week. The amount reduced varies depending on the item. She wants to know how many weeks it will take before the furniture is marked down to half of the starting price. For 1 example, she may deduct 20 after the first week, 19 after the second week, 18 after the third week, and so on.

The Facts

Each time Mrs. Nguyen receives a piece of furniture in the thrift shop, she gives it a price. Each week the item remains in the thrift shop, she reduces the price.
Sometimes the price reductions are 20 , 19 , 18 , 17 , and so on. Sometimes the price reductions are 15 , 14 , 13 , 12 , and so on. 1 Sometimes the price reductions are 12 , 11 , 10 , 1 , and so on. 9

The price reductions stop when the sale price is about 1 of the original 2 price.

The Task

1. Your team will make a chart showing the following information: Beginning price for one piece of furniture Reduced prices of the piece of furniture using each of the three different discount patterns Fraction amount and dollar amount of the price reduction each week Number of weeks before the price is about 1 of the original price for 2 each of the three discount patterns 2. Each team member will write an explanation of the teams work, answering these questions: What patterns did your team find in the calculated numbers? Why do you suppose the patterns occurred?
How many weeks did it take to get to 1 the original price? Did all of the 2 discount patterns take the same number of weeks to get to 1 the 2 original price? Why do you suppose that happened? Which of the three price discounts do you think is the best? Explain your answer.
3. Your team will present this information to the class. Be prepared to explain how you calculated each amount and to discuss the patterns you found.

Using the TI-15

24 U X 24 V Y

24 V 24 U 8