Warning, spoilers ahead:
Above is a four feature solution for the die.
Feature 1 extrudes the cube. Feature 2 is a revolved cut to form a single pip. Feature 3 is a 3D sketch with a point location for all remaining pips. Feature 4 is a sketch based pattern to duplicate the cut revolve at each pip location.
The solution may not even be apparent from the above image. Feature 1 is a simple extrusion to form the cube. Feature 2 is a Hole Wizard feature made with a 3D sketch.
Who knew you'd learn so much solving puzzles?