Like the computer or piano keyboards, the QB offers a full 10 finger capability
Any 5×5 segment of the qb keypad presents a two octave chromatic scale. The key, in the lower left-hand corner, gives the letter name of the scale; the key, in the upper right-hand corner, is the same letter name, two octaves higher. This gives a five finger exercise to either hand. Notice how logical this is-no finger crossing.