HOW CAN I DO A PERFECT SOMERSAULT AND KEEP MY BALANCE?

Over the last month our students in third grade have improved their balance in our P.E. classes and they have done the perfect somersault with different sports equipment such as beanbags, cones, benches, sticks, balance platforms and stilts.  Also they have strengthened their ankles, knees and hips with these exercises, well known as the propioceptive balance.
This is the video with these kind of activities.