How do I repeat an entry on my Ativa AT-P500 calculator without having to enter the number on the keys?

Hi Steven:
You should be able to key in the number, then press (memory plus).
After that, press (clear) once. That should leave the number in memory but leave the display at zeroes.
- 1) Then you would enter your number, Press (divide) symbol, then press (memory recall), then press (equals).
The answer should display. Press (clear) once. resets to zero
- Repeat (1) as above for next numbers.
Hope this helps.
Cheers.

Try pressing an operation key twice.
For example to multiply any entry by 15, you would enter 15, press the multiplication key twice. Now to calculate the products of you list of entries by 15, you just enter number in your then press =. c.then the second number and =, etc.

Scientific calculator
The most basic scientific calculator can do simple 1-variable statistics. Usually you put the calculator in STATistics Mode, then CLEAR all statistics data that may already be stored.
You enter a data value by typing in the number then pressing a key marked DATA. The calculator may display the number 1 for the 1st point. Then as you enter more values, the display shows number that increase by 1.
Once you finish entering data values, you may have to press AC button to exit the data entry phase.
Then you look for the second function (2nd 2ndF, or SHIFT) of some keys. The one marked with an x with a bar on top give the average, the one with marked n give the number of data entered. You may have other keys with the Greek Capital Letter SIGMA. They give various results such as sum of squares, etc. Check your manual for more details.
Newer calculators allow you to use the frequency if there are repeated values. I cannot say more because I do n ot have the make and model of the calculator.

Unlike TI calculators, the HP 12c doesn't have or need a CPT button. It knows whether you've made a numeric entry or not. To calculate N, I, PV, FV, or PMT, simply press the appropriate key without entering a number.

At the top left of the calculator, you will see a sliding switch that is labeled: DECIMAL A,0,2,4,6,F. Move the indicator to the "0". This will remove all excess zeros. The numbers represent how many decimal places the screen will show.

Here is a detailed account of how to calculate the determinant of a square matrix.

I assume you know how to define your matrix, but I will repeat it here for others who might not know. You can skip to Calculation
1.Turn Calculator ON. If there are no icons, press [MENU].

Data Entry
2.Use arrows to highlight [MAT] icon. Press [ENTER]
3.Highlight the first line where it says Mat A. Use the right arrow to enter the dimensions of Matrix A. Enter 3 and press [EXE]. The cursor moves to the second dimension. Press 3 and press [ENTER].
4. The matrix entry screen appears.
5. Enter first matrix coefficient a_11 and press [ENTER]
6. Enter a_12 and [ENTER]
.....
Key in last coefficient a_33 and press [ENTER]

Calculation
Press [MENU] and [RUN]
Press [OPTN][F2:MAT][F3:Det] Command echoes on screen as det
Press [F1:Mat] echoes on screen as Mat; screen shows det Mat
Press [ALPHA] A The screen displays det Mat A
Press [ENTER] to calculate the determinant.

If the matrix is not square, you cannot calculate its determinant.

When you press the OPTN key you see Tabs at the bottom of the screen. The second one from the left should be the submenu for matrix operations.. When you press F2:MAT, the new tabs are Mat, M>L (Matrix to List), det (command to calculate the determinant etc.

Here is a detailed account of how to calculate the determinant of a square matrix.

I assume you know how to define your matrix, but I will repeat it here for others who might not know. You can skip to Calculation
1.Turn Calculator ON. If there are no icons, press [MENU].

Data Entry
2.Use arrows to highlight [MAT] icon. Press [ENTER]
3.Highlight the first line where it says Mat A. Use the right arrow to enter the dimensions of Matrix A. Enter 3 and press [EXE]. The cursor moves to the second dimension. Press 3 and press [ENTER].
4. The matrix entry screen appears.
5. Enter first matrix coefficient a_11 and press [ENTER]
6. Enter a_12 and [ENTER]
.....
Key in last coefficient a_33 and press [ENTER]

Calculation
Press [MENU] and [RUN]
Press [OPTN][F2:MAT][F3:Det] Command echoes on screen as det
Press [F1:Mat] echoes on screen as Mat; screen shows det Mat
Press [ALPHA] A The screen displays det Mat A
Press [ENTER] to calculate the determinant.

If the matrix is not square, you cannot calculate its determinant.

PRINT KEY: To save paper you can only print what is displayed, even in non-print mode. Pressing after the entry of a number will print the entry with the symbol “#” even in non-print mode. Pressing will insert a separator into a number entry such as a code, date, etc. Separators are displayed as a period and dashes but printed as periods. MEMORY + KEY / PRINT ON / OFF KEY: Pressing selects print mode or non-print mode. Cause the calculator to operate in a display / print or display only mode, depending upon the calculator’s present state. “P” on the display: Print mode. “NP” on the display: Non-print mode. MEMORY – KEY / DECIMAL SELECTION KEY: Pressing sets the number of decimal places in the result. “F” on the display: The answer is displayed in the floating decimal system. “3, 2, 1, 0” on the display: Presets the number of decimal places in the answer. “A” on the display (Add mode): The decimal point in addition and subtraction entries is automatically positioned to the 2nd digit from the lowest digit of entry number. Use of the add mode permits addition and subtraction of numbers without entry of the decimal point. Use of , and will automatically override the add mode and decimally correct answers will be printed.

I have the same problem (no manual) but solved it: the port of entry for the paper feed in located on the back, near the bottom. The top piece (where you tear the paper off) moves slightly to the back and can be removed. Feed the paper into the machine; pull out a few inches asnd cut the edges of the paper, about two inches back, into a "V" and feed this point into the slot just below the "ridge" and press "feed". Problem solved!

Go to messages, new message, go to the menu(middle button) select entry options/method/settings, go to primary and select TAP English, go to Secondary and select None.
Text-Entry Methods:
iTAP - Lets you enter words using one key press per letter. The iTAP® method combines your key presses into common words and predicts each word as you enter it.
TAP - Lets you enter letters and numbers by pressing a key repeatedly to cycle through the letters and number on that particular key.
TAP Extended - Same as TAP, but cycles through additional special characters and symbols as you repeatedly press a key.
Text-Entry Modes:
Primary - You can set your Primary entry mode to any iTAP or TAP entry method.
Secondary – You can set your Secondary entry mode to any iTAP or Tap entry method, or you can set it to None if you do not want a Secondary entry mode.
Numeric - Enter numbers by pressing the number keys.
Symbol - Enter symbols by pressing a key; its symbols are displayed at the bottom of the screen. Scroll to the desired symbol and then press Select.
To set the text-entry mode or method:

• From a text-entry screen, press Options.
• Scroll to and select Entry Setup or Text Setup.
• Select the desired text-entry mode or method.

Tip: From any text entry-screen, you can quickly change your text-entry mode without leaving that screen. Press the # key repeatedly to cycle through the text-entry modes: Primary, Secondary, Numeric, and Symbol. With each press of the # key, the mode indicator in the upper left of the text-entry screen changes.