STARTING POSITION:
Sit on a high chair, your feet should not touch the floor.
MOVEMENT:
Moving only your ankle, raise the right toe as much as you can. Now using your soleus and gastrocnemius, extend the ankle as much as you can. Repeat the movement for the specified amount of repetitions and then repeat with the other leg.
TIPS: The exercise key is quality over quantity. The trick is to perform the exercise using proper form.