Overview
You may choose to display either 10 or 15 columns for assignments. The 15-column view saves space by showing only the first 4 characters of the assignment title on the gradebook spreadsheet. With 10 columns you will see the first 12 characters of the assignment title. Either way, hovering over an assignment title produces a small pop-up window in which the full assignment title is displayed along with the essential assignment details.
Step-By-Step Guide
1. Click the Settings link (the gear icon) on the top right corner of the page.
2. Select any of your Gradebooks from the Gradebook Settings section.
3. In the Number of Columns in Gradebook section, click Go.
4. Choose the number of columns in the Display section (e.g. 10 or 15).
5. Click Submit. 
Confirmation
Assignments are displayed based on the number of columns that has been set.