While selecting a number of cells, it’s easy to accidentally click on a cell you didn’t intend to include. But you don’t have to start over with your selection after every misclick. You can deselect the mistakes.
Press and hold the [Ctrl] key while clicking on any cells you want to deselect. While holding down [Ctrl], you can also click on any additional cells you want to add to your selection.
This feature is only available with an Office 365 subscription.