How to use scientific calculator

The first thing that catches your eye of scientific calculator is the four buttons on both sides of the direction key. The two buttons on the left are SHIFT and ALPHA (this button will be introduced later), and the MODE button on the right is not often used by many people and may not be well understood. Now I'll spread it out for you.

Press the MODE key, and 1(COMP), 2(SD) and 3(REG) will appear, which are the specified calculation modes. COMP is the basic arithmetic operation, SD is the standard deviation, and REG is the regression calculation. Basic arithmetic operations are addition and subtraction multipliers, and sometimes more advanced operations, such as percentage and square root, are included. The standard deviation calculation mode can do almost all the data of statistical calculation, and the calculation process can be carried out according to the following figure. Of course, you must enter SD mode first, that is, the mode key 2 key enters SD mode. What needs to be added here is that the standard deviation is the standard deviation of the sample. Let me introduce the use process below. Enter the data to be calculated after entering the mode, for example: 55, 54, 55, 5 1, 53, 53, 54, 52; The input process in SD mode is 55 DT (see the figure below), 54dt55dt5 1dt53dt54 52dt, and then the calculation is started. (Press the picture button)

The result of calculating the standard deviation of the sample is:/kloc-0 1.30000.0000000605 The key pressing process is: SHIFT S-VAR 3 =；;

The result of calculating the deviation of the parent sample is:1.316956719; The key-pressing process is: SHIFT S-VAR 2 =；;

The arithmetic average is: 53.375; The key-pressing process is: shift s-var1=;

Number of data: 8; The key-pressing process is: SHIFT S-SUM 3 =；;

The total data is: 427; The key-pressing process is: SHIFT S-SUM 2 =；;

The sum of squares of data is: 22805; The key-pressing process is: shift s-sum1=;

Regression calculation is a statistical analysis method to determine the quantitative relationship between two or more variables, which will not be expanded here. The calculation is complicated and is what engineers want to do.

Careful friends will notice that there is a CLR written in yellow next to the MODE key. This is the data clear button. The step to start it is to press SHIFT first and then CLR, and there are three ways to clear it. Select 2 to clear the mode, and select 3 to clear it all.

Introduction to double-click mode key

Double-click mode will bring up 1 (degree), 2 (radian) and 3(GRA). Deg stands for "degree" in the angle, Rad stands for "radian" in the angle, and Gra stands for "gradient" in the angle. The latter two concepts will appear in college mathematics, but if mathematics is not good, don't say it, how to operate it specifically. Have you noticed that the indicator D of DEG is always on, and it is selected by default when the calculator is turned on, so it can be understood as a decimal indicator. In short, for the average person, the function of pressing MODE twice is basically useless.

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Introduction of pressing the mode key three times

At this time, 1 (repair), 2(Sci) and 3 (specification) will appear. Fix refers to the number of decimal places reserved, Sci refers to the number of decimal places reserved by scientific counting method, and Norm refers to the normal mode (it seems useless). If there is nothing to choose these functions, we basically don't need them, and we will be distressed because we don't know how to restore them after choosing them. The easiest way is to press the reset key, or press mode three times to select the third norm, so that we can recover.

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Introduction of other keys that are not commonly used:

The red ABCDEF is the hexadecimal representation of 16;

NCr is a permutation and combination;

Pol (is the key of complex number calculation, which is used to convert Euler formula and general formula;

By pressing the RCL button, the user can call up the data originally stored in the calculator memory. The RCL button usually exists at the same time as the STO button, which can write the data currently displayed on the calculator screen into memory. RCL is the reverse process of this process.

Eng: Turn it into a scientific counting method (like a useless button).