Yes that is a great idea. Let him use whatever fingers he wants to until he knows the piece dry well. Preferably from memory. At this point the will be room in his conscious that to learn something else. You don't want him to be thinking about of much at once or he will get frustrated.
You can show the video ( check the forum index for learning videos) for the song he is learning and point out the different fingers the player uses but don't push too much until he has the song well under control.
Keep it up you are doing great!
Isaac has also started on HCB which I posted in the recital. He plays R and L hands separately. Still likes to play with two fingers on the bass clef. I guess his fingers are not that strong yet, but we have tried to play it with one hand today., which is still struggling as he hasn't got the strength yet, so I have just allowed him to play with his two fingers which he enjoys.
I will repost the two videos I posted in the recital category.
1. Isaac plays 'Ode to Joy' Right hand. He can do the left as well, but I didn't record it. He can also play it from memory, although he has some extra notes which he plays and goes in a loop sometimes.
2. Isaac plays ' Hot Cross Buns' right hand only. He can also play this from memory.
Isaac has now been practising the songs with position 1,2,3,4.
I have also started the flash cards ' RE' to 'RE' as suggested by you and it seems harder than ' Do' to 'Do' for him. I think it just a matter of getting use to it.
I have also given him the Broken Chord Waltz to play and he enjoys playing 'Do' 'Me' 'So' broken chords in the left hand. That's the new thing he is playing at the moment since he still can't put two hands together.
Isaac has also been playing Guess Key, but his attention on it is not consistent. We tried the NOte Duration game with me holding his finger and pressing it as sometimes when he presses, the game hangs after a couple of presses (don't know why this happens).
As for the treble and bass clef puzzle and fruit lines, I have to help him with the computer skills while he calls out the right notes.
Is there any ideas of how other families have showed the notes and treble and bass clef staff on paper? I know someone did it with cars. Just want some ideas before I start making it for my son. He wanted to use the flash cards to write the song ' Ode to Joy'. He can't really write yet. Any ideas would be helpful.
Last week Isaac has been learning to play the LH part for Ode to Joy and Hot Cross Bun using one hand and today, out of the blue he started putting two hands together for both songs and tried to do it by memory. Will have to film him once he gets better at it and reading the score too.