This chapter gives the student a chance to reacquaint himself with basic calculator operations.

The teaching of the "mechanics of mathematics" (division, multiplication, logarithms, etc.) in recent years has focused more on the skills of using a calculator than on the pure principles of the basic subject material. With the decreased cost of hand calculators, virtually every person owns, or has access to, a calculator. A nuclear plant operator would be wise to learn how to use most of the calculators available today. Such knowledge will help the operator make quick decisions when circumstances arise for the need of a "quick calculation" of flow rate or some other parameter.

Many calculators are available on the market today, and each one is a little different. For the purpose of this module, a scientific calculator will be needed. The Texas Instruments scientific calculator TI-30 will be used for the examples in this module. Most calculators work on the same principles, but some do not. Some calculators operate on a programming principle like Hewlett-Packard (HP). An HP calculator does not use an equal key. To perform a mathematical operation, the first number is inserted, the ENTER key is pressed, the second number is inserted, and then the mathematical function key is pressed. The result will be displayed. If a different calculator is used, the student will need to refer to the reference manual for his or her calculator.

The following section will review the general use function keys on a TI-30 calculator. In each following chapter of this module, the applicable calculator operations will be addressed.

Appendix A of this module gives a representation of a TI-30 keyboard to assist the student.

Keys

Clear entry/Clear key

Pressing this key once will clear the last operation and the display. Pressing this key twice will clear all operations except the memory.

Note: To clear the memory, press clear then STO.

Note: Many brands break this function into two separate keys, usually labeled "clear" and "all clear," where the "clear" key clears the last entry and the "all clear" key clears the display and all pending operations.

Memory Key

The TI-30 has only one memory. Pressing the STO key enters the displayed number into memory. Any number already in memory will be overwritten.

STC

Note: Calculators with more than one memory will require a number to be entered with the STO key. For example, STO 01 means store the displayed number in memory 01; STO 20 means store the number in memory 20.

Memory Recall Key

Pressing the RCL key will retrieve the number in memory and display it. Note that the number is also still in memory. This allows the number to be used again. Pressing the RCL will also overwrite any number previously displayed.

Note: Calculators with more than one memory will require a number to be entered with the RCL key. RCL 01 means recall the number stored in the 01 memory. RCL 20 means recall the number stored in memory 20.

Constant Key

Certain calculations often contain repetitive operations and numbers. The K, constant, is a time-saving function that allows a single key stroke to perform a single operation and number on the displayed number.

For example, if 20 numbers are to be multiplied by -17.35, the K key can be used. Enter -17.35, then press the times key, then the K key; this "teaches" the calculator the required operation. From this point on when entering a number and pressing the K key, the calculator will automatically multiply the displayed number by -17.35, saving you six key strokes.

Summation Key

If a long list of numbers is to be added, the summation key will save time if used. Pressing the summation key adds the displayed number to the number in memory. The final sum is then retrieved from memory.

sum

Memory Exchange Key

The EXC, memory exchange key, swaps the displayed number with the number in memory.

Reciprocal Key

When pressed, it divides the displayed number into one.