A piano has 88 keys, but there are only twelve different ones, repeated from the bottom to the top: seven white keys and five black keys. Look at the black keys: they come in groups of two and three. That pattern is how pianists find their way without looking for labels.
The white keys are named with the first seven letters of the alphabet: A B C D E F G, and then the letters start again. Every key with the same letter sounds like the same note, just higher or lower.
Start with C. It's the white key just left of each group of two black keys. From there, the white keys going right are C D E F G A B, and then the next C. Two more landmarks: F is just left of each group of three black keys, and E and B are the two white keys with no black key on their right.
To play here, use the keyboard on the screen (tap it, or click), a MIDI keyboard plugged into your computer or tablet, or the computer keys: A S D F G H J K are the white keys from C, and W E T Y U are the black keys between them.
One octave of the keyboard. The pattern of two and three black keys repeats all the way up.
Practice
The landmarks
Find each landmark. Any of them on the keyboard counts.
C3DEFGABAC4SDDEFFGGHAJBKC5WETYU
Computer keys: ASD… for the white keys, WET… for the black keys, ZX move an octave.
More info
Tips
Look at the black keys, not the white ones: the twos and threes are easy to spot even without looking straight at them.
Say the names out loud as you play. It's a small thing that makes them stick much faster.
Playing the exercises
Use a MIDI keyboard (Chrome, Edge, Firefox or Opera), the computer keys (ASD… for white keys, WET… for black keys, ZX to move an octave), or tap the keys on the screen. A key lights up after a couple of wrong tries.
The answers
How do you find C on a piano? The white key just left of the two black keys. C sits just left of each pair of black keys. F sits left of each group of three.
Which white keys have no black key on their right? E and B. E and B are followed straight away by F and C, with no black key between them.
What comes after G in the white keys going up? A. The letters only go up to G, then start again at A.
How many different keys repeat up and down the piano? Twelve. Seven white and five black keys make twelve, and that group repeats all the way up the 88 keys.