### Calculators

One of the most important tools you have is your calculator; and, while the amount of daily math necessary for the trade is smaller today than it was, there is still enough to make learning calculators and math necessary.

Not any old calculator will do! It must be a scientific calculator similar to the one shown in figure 1. Simpler calculators that only add, subtract, multiply, and divide is not capable of solving the math problems that will be encountered: trigonometry, for example.

All calculators are a little different: in look, layout and sometimes the way they function. They are, however, basically the same, and are made up of four different sections: the readout screen; On-Off, mode and shift keys; the function keys; and the number and basic math Figure 2 function keypad.

This first row of five includes the “shift” key. Depending on the manufacturer, this key is also known as: “2nd function” or the “Inverse Function” key. Its purpose is to change the key function from what is called on the key to the function printed on the body of the calculator above the key.

The Alpha Key allows for the use of letters and special characters, while the large center pad is a mouse for paging around the screen.

The “Mode” key sets the appropriate calculation mode, for example, COMP: basic arithmetic calculations (arithmetic operations, trigonometric functions, etc.) or COMPLEX: complex number calculations. There are more for statistics and working with base numbers.

The “Setup” key calls a list of display options: do you want to get your answer as a fraction or exponent; how many decimal places?

The last key is the On/Off key.

**Function Keys**

The next section of the calculator is the “function” keys. Amongst them are square and square roots, trigonometric functions and Degree, Minutes and Seconds, figure 3. Note the yellow writing above each key these are the shift or second functions that are evoked if the shift key is depressed first.

Now, look at figure 3. In the lower left corner is the “**RCL**” key; this recalls formulas from memory. If the object is to store a value into memory, the process would be shift RCL. The shift key calls the “**STO**” function, printed above the key. Depressing the RCL key to making it happen. The **M+**,** M**, and the **M-** key to add to, recall and clear data.

Along the third row, the last three keys are the Trig Function Keys:

**Sine**, **Cosine**, and **Tangent**.

Above the keys are the “Arc signs” or inverse trigonometric functions. These three keys are the main reason for needing the scientific calculator. These are used to solve triangles, find missing dimensions or calculate bend deductions, figure 4.

Note that through the use of the Parentheses Key, many formulas can be directly keyed into the calculator so you do not the need to keep notes while you are calculating, figure 5.

The final section has the basic number key pad and basic math function keys: add, subtract, multiply and divide, along with delete and all clear (AC). Some of these keys also have the second or shift functions printed above the keys.

Note that on some calculators there may also be a “mode” key.

One last note before the video: make sure that your calculator is in Degree mode and not set to Radians or Graduations. If the calculator is not in Degree mode, the formulas contained in the remainder of the book will not work properly.

**Video**

This video is titled *Calculator Math* courtesy of Asma, LLC covering basic math and calculator operations.