The following example demonstrates the C major scale played with the left hand and then both hands together. The left hand fingering is the reverse of that of the right hand. The crossover occurs between G and A. When playing the scale with both hands together, the crossovers occur at different times with each hand, so take care not to lose your timing at these points. Play very slowly at first and only increase the speed once you can play the whole example smoothly and evenly.
Here is a new version of the song you learned in lesson 5. This time the melody is played with the left hand. Practice each hand separately if you need to.