[ltp] Stupid keyboard question

[John Jason Jordan]

I have had my new T61 for only a couple of months. I noticed the other
day that the keys on the right side of the keyboard have extra
characters on them. For example, next to the 7, 8, 9 and 0 are a
smaller 7, 8, 9 and /. Next to the U, I, O and P are a smaller 4, 5, 6
and *. The next two lines down also have extra characters. 

I suppose it doesn't matter, but I'm curious. What are these for?