Here comes the fun part! Excel formulas! Formulas are equations that perform calculations on values in your worksheet. A formula always starts with an equal sign (=), (+), and (-).

You can create a simple formula by using constants and calculation operators. For example, the formula

**=1+2*3**multiplies two numbers and then adds a number to the result. Excel follows the standard order of mathematical operations. In the preceding example, the multiplication operation (**2*3**) is performed first, and then**1**is added to its result.Depending on the type of formula that you create, a formula can contain any or all of the following parts.

**1**

**Functions**

A function, such as

**PI()**, starts with an equal sign (**=**). For many functions, such as**SUM()**, you can enter arguments within its parentheses. Each function has a specific argument syntax. Some arguments require exactly one argument, others require or allow several arguments (that is, some arguments might be optional), and some other functions allow no arguments at all — such as**PI()**.**2 Cell references**

You can refer to data in worksheet cells by including cell references in the formula. For example, the cell reference

**A2**returns the value of that cell or uses that value in the calculation.**3 Constants**

You can also enter constants, such as numbers (such as

**2**) or text values, directly into a formula.**4 Operators**

Operators are the symbols that are used to specify the type of calculation that you want the formula to perform. For example, the ^ (caret) operator raises a number to a power, and the * (asterisk) operator multiplies numbers.