Year 4, how to improve

[LifeChangingMe]

My son is very behind in his writing, reading and maths. He is though a very bright boy (was educated Waldorf (withheld academics until 7) then he went to a state school at 7 and hasn't caught up). I desperately need to help him catch up with his peers so his work will reflect his intelligence. His writing is poorly formed and BIG his spelling is poor. He forms neat letters in a handwriting book but when it comes to writing for work it reverts back.
What is the best way to help him improve in numeracy and literacy?

For maths, if he can get his Times tables and number bonds down it will really help the rest of his maths too. Look on YouTube for times tables songs, and Farmer Pete has a good number bonds to 10 song on there too. Shut The Box (the game) gives good number bond practice. I have some links somewhere on other ways to help with number bonds; I'll see if I can find them.