These are delightful-sounding short pieces, with very clear Classical era influences.
The first one, with the mix of triplets, seems to be a sort of practice in keeping time.
The second one, a practice on left hand tone control -- with all the chords in there.
The third one - my favourite - reminds me a little of Mozart's K.545 3rd movement (not the tune, but the general concept of the piece). Feels like an exercise on clarity.
Nice work!