iCloud stores your spreadsheets and keeps them up to date across your iOS devices, the web, and your computer so that you always have the most current versions at hand, no matter which device you used to make your latest edits.
You can also edit Numbers spreadsheets in a web browser using Numbers for iCloud Beta. Numbers for iCloud Beta is a web app that allows you to create and edit Numbers spreadsheets using a supported web browser from a Mac or Windows computer.
Spreadsheets you create using Numbers for iCloud Beta are automatically available in Numbers on your Mac or iOS devices that are set up to use iCloud—and vice versa: if you create a spreadsheet using Numbers on an iOS device or Mac, it appears automatically on the web in Numbers for iCloud Beta.
For help using Numbers for iCloud Beta, click the Help button in the Numbers for iCloud Beta spreadsheet manager, then choose Get Help. If you’re working in a spreadsheet, choose Tools > Help.
Open System Preferences on your Mac, then click iCloud.
Sign in using your Apple ID, or request a new Apple ID and then sign in.
Select the Documents & Data checkbox, then click Options.
Select the Numbers checkbox, then click Done.
Here are a few things to keep in mind about using iCloud to manage your spreadsheets across devices:
If you edit and close a spreadsheet when you're not connected to the Internet, an upward-pointing arrow appears in the spreadsheet thumbnail. The next time you connect to the Internet, the edited spreadsheet is saved to iCloud.
If you edit a spreadsheet on more than one device before saving any of your changes to iCloud, you will get conflicts. To avoid conflicts, make sure your edits are always saved to iCloud before editing the same spreadsheet on another device. If you do get a conflict, you can choose to preserve any or all of the spreadsheets that you edited.
If you delete a spreadsheet, it’s deleted from iCloud and from Numbers on all your devices.
If you organize your spreadsheets into folders on one device, you see the same folder organization on all your devices.
If you change the title of a spreadsheet on one device, the title is changed on all your devices.