In western music, we name the different pitches of notes by the first seven letters of the alphabet: A, B, C, D, E, F and G.
A keyboard has groups of two black notes followed by a group of three black notes.
We can find where the note A is on a keyboard as it’s always between the second and third black notes in the group of three as shown below:
From here we can then work out what all the white notes are.
We go through the alphabet until we reach the note G, then we start over again back at A.