How do u play a scale? Well, for any scale when you are going up the keyboard, you tuck your finger under. When you are going down the keyboard, you cross your finger over. Here is a detailed explanation of how to play the C major scale:

Numbers correspond to fingers:

thumb = 1

index = 2

middle = 3

ring = 4

pinky = 5

RH: 1 2 3 1 2 3 4 1 2 3 1 2 3 4 5

LH: 5 4 3 2 1 3 2 1 4 3 2 1 3 2 1 (RH in reverse)

RH forward: (1)thumb, (2)index, (3)middle, tuck (1)thumb, (2)index, (3)middle, (4)ring, tuck (1)thumb, (2)index, (3)middle, tuck (1)thumb, (2)index, (3)middle, (4)ring, (5)pinky

RH backward: (5)pinky, (4)ring, (3)middle, (2)index, (1)thumb, cross (3)middle, (2)index, (1)thumb, cross (4)ring, (3)middle, (2)index, (1)thumb, cross (3)middle, (2) index, (1) thumb

LH forward: (5)pinky, (4)ring, (3)middle, (2)index, (1)thumb, cross (3)middle, (2)index, (1)thumb, cross (4)ring, (3)middle, (2)index, (1)thumb, cross (3)middle, (2) index, (1) thumb

LH backward: (1)thumb, (2)index, (3)middle, tuck (1)thumb, (2)index, (3)middle, (4)ring, tuck (1)thumb, (2)index, (3)middle, tuck (1)thumb, (2)index, (3)middle, (4)ring, (5)pinky

*As you play this scale, make sure to keep your arms straight and your fingers curved. Use the same technique that use to type on a computer keyboard.

Try to use this information to figure out how to play the other scales. If you still having trouble, just let me know.