palmtree67, I am sure you have some special gift.
Memory is something that can be exercised by relating things that you want to remember in real bizzar ways. Like if you want to remember that you left your eye glasses on a television set, imagine lightning striking the antenna and electric current running all the way thru the wires and thru the tv then your eyeglasses glowing with light. That is the basics on how to exercise the memory. To remember combonations of numbers try adding parts that equal another number or relate the numbers with something else you all ready know. I have heard of people relating numbers and other thing to colors. Find what works for you and keep doing it and it gets better.
To do large math in my head I added or subtract or what ever by imaginary 0's then put the numbers back in when I was done. It has been a long time sense I have done it so it would take some time to remember just how I did it.
I did not know I could do algebra until about a year ago. I have noticed lately I can't remember how to spell a lot of words lately.
Take Care