Excel comes with built-in formulas known as **functions**. You can use these functions to do calculation and solve your problems.

Example of function: =SUM(A1:A3)

You can also create your own **formulas**.

Example of formula: =A1,A2,A3

**Please note**: A function or formula will always start with = sign.

## Formulas in Excel

Formulas are different from Functions. In mathematical term, a formula is an expression that user creates to calculate values in a cell or in a range of cells.

For example:

If A1 has 24, A2 has 35 and A3 has 54, to add these values using a formula, we can write: =A1+A2+A3

If we do not want to use cell reference, we can directly add the numbers in a cell writing: =24+35+54

To use formulas, we’ll have to create the formula. We’ll have to use the appropriate signs like +, -, *, / etc.

## Functions in Excel

To make our work more easy in calculating, Microsoft Excel develops functions that we can use in calculating values. These functions are built-in and comes bundled within Excel.

**A function always includes ( ) after the function name.**

For example:

To add two numbers 34 and 45, we can use SUM function as: =SUM(34,45)

If the numbers are different cells, like A1 has 34 and A2 has 45, we can use SUM function as: =SUM(A1,A2)

There are many functions in Excel that we can check, however, we will cover the basic functions that we use and may need in our personal life.

Let’s continue to the next chapter about basic functions.