This is how a piano accordion keyboard looks.

The right hand of a piano accordion is played the same way as you would play a piano, with usually the same fingerings. You can use all fingers, including the thumb, to play on this keyboard.

On a standard, full-sized, the range of the keyboard goes from the "F" below the middle "C", all the way up to the third "A" above middle "C" (41 notes). Some large instruments have 44 or even 45 keys, going from an "E" or "F" to a high "C".