There are three modes or views for the main spreadsheet of the gradebook. Use the Mode menu located near the top left the gradebook spreadsheet to switch modes.
The default mode for the gradebook is "Points". In this mode, all grades are editable on the main gradebook spreadsheet.
"Locked" mode is the same as locking scores on the current gradebook. Only empty cells are editable in this mode. All saved scores are locked.
This mode displays all scores as percentages of the maximum. In the "Percent" mode, all scores, empty or saved, are locked.