# Add formulas & functions

You can perform many different types of calculations by using functions to create formulas in Google Sheets. Here's a list of all the functions available.

## Create a formula

- On your iPhone or iPad, open a spreadsheet in the Google Sheets app.
- Tap the cell where you want to add the formula.
- To pick from a list of functions, tap Function . Then choose a category and pick the function you want to use in your formula.
- To enter a function manually, enter
`=`

and the function you want to use. - If the cell already has a formula in it, skip to step 5.

- A description of the function will show as you’re working on it to guide you through formula creation.
- To use the content of other cells in your formula equation, type the names of the cells into the formula.
- Choose from the symbols below the text box to add to the formula. For example, to subtract the contents of one cell from another, tap the
**-****(minus)**symbol. - To finish the formula, tap Done .

## Additional features for creating formulas

Nested functionsA function used in the same cell with another function is called a nested function. When functions are combined, Google Sheets will calculate the innermost function first. The nested function is contained in parentheses and is used as one of the components of the surrounding function.

For example, let's say you want to calculate the absolute value of a sum of several numbers in the cell range A1:A7. To calculate the sum of these numbers, you would enter '=SUM(A1:A7)' into a cell.

To calculate the absolute value of this sum, you need to nest the sum formula within absolute value formula. To calculate both formulas in a single cell, enter '=ABS(SUM(A1:A7))' into the cell. Note that the =SUM() function is performed first and is used as a component in the =ABS() function.

When you reference other cells in a formula, those cells will be highlighted those cells in contrasting colors to help you more easily build a formula. When you tap a cell that contains a completed formula, you'll also see these cells highlighted.