When I learn telephone numbers, I remember them as Area Code, Group of 3 numbers, second group of 3 numbers, much like ElectricSheep.
Mental Arithmetic is not my strong point, I can do sums in my head, but it takes me a long time because I have to rearrange the numbers in my head(for multiplication) to make it a sum I can do in my head, easily.
For example, I wanted to multiply 0.56 by 350 in my head(I was in bed and couldn't be bothered to find my calculator), so I made it into 56x3.5, then 28x7, then 7x4x7, then 49x4 to get the answer of 196.
If it's a spoken sum, I have to write down the main numbers involved because I forget them quickly. Even simple sums...
And when I'm counting, I can never remember what comes after 79, I always stop and think about it, for some reason. I know it's 80 but can never remember it...
And I'm doing a Further Maths A-Level and hoping to do Maths at University...
Jam it back in, in the dark.