The right and left hands play alternately, creating a single melody. To prevent the right and left hands from colliding or obstructing each other, keep the left wrist high and play towards the back of the keys. Conversely, for the right hand to always pass smoothly under the left hand, keep the wrist low and play towards the front of the keys. Towards the end of the Burnam Piano Technique: A Dozen a Day, Preparatory Book, there is an exercise called 'Piggyback Ride' (肩ぐるま), which involves alternately playing D and F with the right hand and D# and F# with the left hand; similarly, the hands will assume a 'piggyback' posture in this piece. Initially, playing towards the back of the keys may be challenging, but since one must be able to play freely both at the front and back of the keys, please do give it a try. The tempo is marked Allegro, and while ideally it should be played with exhilarating speed, I believe it is quite difficult for young children. Nevertheless, I believe it is an etude worth attempting even at a slow tempo.