# Arithmetic

You may type arithmetic operations into the equation editor using the standard Nemeth braille symbols.

You may type an infix operation (like plus) by typing the number to the left of the operation, followed by the operator, followed by the number on the right of the operation, just as you would if you were to write the equation on paper.

Two or more operations may be entered in the natural left-to-right order, and the equation editor will use the natural order of operations to produce the proper expression.

There are three kinds of multiplication symbols: times sign (dot 4 dots 16), times dot (dots 16), and times asterisk (dot 4 dots 3456). There are also two types of division symbols, division sign (dots 46 dots 34) and division slash (dots 456 dots 34). These symbols are defined by the Nemeth code, and supported by the equation editor. The division slash is an example of an operation that uses an open and close symbol, which will be covered in more detail in a later topic. For now, you may type the symbol, and observe that the equation editor will supply the open and close symbols for you.

## Exercises

Type the following expressions into the equation editor below and verify that the equation editor produces the proper Nemeth braille output in each case. Also verify that a sighted friend can read each expression you have typed as it is displayed on the screen. Try each of the three alternative multiplication symbols, and each of the two division symbols. Feel free to try your own examples.

- 123 + 456
- 987 - 654
- 531 * 248
- 512 / 32
- 2 + 3 * 5