A major scale is a group of eight notes that gives the familiar sound: DO RE MI FA SO LA TI DO. You now know enough notes to play the C major scale. To play the C major scale smoothly you will need to play the F note with your thumb. Do this by moving your thumb underneath your second and third fingers on the way up the scale. On the way down the scale, move your second and third fingers over your thumb. This is called the crossover.
It is important to practice scales up and down every day.
An octave is the range of eight notes of a major scale. The first note and the last note of a major scale always have the same name. In the C major scale, the distance from Middle C to the C note above it (or below it) is one octave (eight notes).