Please help me

Hello all.
Does anybode can help me?
I'm writing my first letetr of recommendation and don't know hot to say in intellegent, formal style.
For example how to say
He has ability to asquare new concepts and ideas quickly and deeply.
He has wide range of interests in Coputer Scince and Mathematics.
How to say something that he like self-education, educate yourself in such areas?
And he coplete his task on time without mistakes.

Many thanks