23b3ae1d_ith_Apple_Keynote___Keynotopia__Purpose
[Menu Item] Fit in Window [Shortcut] CMD+1 [Purpose] 
This shortcut is particularly useful if you’re working on a prototype with dimensions larger than the screen. For instance, I prototype iPad apps in portrait mode, and the 1024px height won’t fit on my 800px laptop screen.
How To create interactive prototypes with Apple Keynote | Keynotopia
Purpose