 How to use the SUM function in Google Sheets
 Write a function in Google Sheets
 How do you write a SUM function?
 How to enter the SUM function in Google Sheets
 Create an amount with a function button
How to use the SUM function in Google Sheets
Adding rows or columns of numbers is one of the most common operations performed in all spreadsheet programs. Google Sheets has a builtin SUM function for this.
If the function is present, the spreadsheet is automatically updated when you make changes to the cell range in the formula. If you change entries or add text to empty cells, the total number of updates includes the new data.
These instructions use the Google Sheets app for iOS. See notes for differences between mobile and desktop versions
Write a function in Google Sheets
A function in Google Sheets — or in other spreadsheet programs like Microsoft Excel — has three parts, in this order:

The equal sign (=). This tells the program that you are entering a function.

The name of the function you are using. This is usually in capital letters, but it doesn’t have to be. Some examples are SUM, ROUNDUP and PRODUCT.

Set of brackets: (). If your function involves working with a series of numbers in your spreadsheet, they are in parentheses to tell the program what data to use in the formula. Some functions, such as NOW, which return the current date and time, still contain parentheses, but they are empty.
How do you write a SUM function?
Using the information above, write a SUM function like this:
= SUM (число_1, число_2, ... число_30)
In this case, the numbers in parentheses are all the individual cells you add. It can be a list like (A1, B2, C10) or a range like (A1:B10). The range option is a way to add columns and rows.
How to enter the SUM function in Google Sheets

Enter the information you want to add to the table. Click or tap the cell where you want to place the formula.

Click Enter text or formula to open the keyboard.

Enter “ =sum(“) to start the formula.

Then you choose which numbers you want to add together. One way to do this is to click on the desired cells. They appear in parentheses in your formula.

To select a range of adjacent cells at once, click one (for example, the first in a row or column), then click and drag the circle to select all the numbers you want to add together.
You can include blank cells in the function.

Close the parentheses “)” to end the function, then click the check mark to start the function.

The function runs and the sum of all the numbers you selected appears in the cell you selected.

If you change any of the values in the selected cells, the sum is automatically updated.
Create an amount with a function button
You can also use the menu to enter a function instead of typing it. Here’s how to do it.

Enter your details and then select the cell where you want the amount to be displayed as before.

Instead of typing your input into the text box, tap or tap function button to her left. The function button looks like the letters “fx”.
On the desktop version of Google Sheets, the function is located in the right corner of the format bar and resembles the Greek letter sigma (∑).

A list of function categories appears. Click Math .
The function menu in the desktop version of Google Sheets contains several commonly used formulas. SUM may be in this list.

The functions are listed in alphabetical order. Scroll down and click SUM .

You return to the table. Enter the range of numbers you want to add as usual.