Open Google Sheets
Put the numbers in Rows or Columns.
Method #1:
Manually add numbers by typing = and then clicking on each number followed by + sign and then the other number.
Method #2:
Select all numbers and look at the bottom of screen to quickly find sum or average of numbers
Method #3:
Press = on keyboard and select all the numbers you wish to find the sum of. Then Press Enter.
Timestamps:
00:16 First Method
00:33 2nd Method
00:46 3rd Method