Step #1
First commence the tutorial by making a dotted rectangle.
Step #2
Draw outline for rectangle.
Step #3
Draw outline for side edges.
Step #4
Outline for dotted rectangle.
Step #5
Make squares for buttons.
Step #6
Make small squares and one rectangle for left side buttons.
Step #7
Draw top buttons.
Step #8
Make dotted line for upper rectangle.
Step #9
Enhance buttons with numbers and signs.
Step #10
Finally, make necessary improvements to finish.