Hexidecimal is Base-16.
Normal decimal is Base-10. This means we have 10 unique symbols for each decimal "place" we count. They are the familiar 0,1,2,3,4,5,6,7,8,9.
In base-10, we can count up to and including 9 "things" in each place. when we count up to 9, we can't go any "higher" in that place, so using rules of base-10 addition, we add one more
unit to the place just to the left, and reset the current place to zero. This is how we go from 9 to 10 in decimal math. (Thank the arabs for this revolution!! This is easier than going from IX to X)
Hexidecimal has 16 unique symbols for each place, meaning you can count up to 15 things for each position. Since we only have 10 symbols for our base-10 math, we have to come up with some extra symbols for those extra 5 units, so we borrow from our alphabet. Let's count to 15 using hexicecimal.
1
2
3
4
5
6
7
8
9
so far so good, just like regular decimal. Now, unlike decimal, we're not done counting in this column yet. Adding 1 to 9 in hexidecimal gives us
A //=10 in decimal
then we count
B // = 11 in decimal
C // = 12 in decimal
D // = 13 in decimal
E // = 14 in decimal
F // = 15 in decimal
Now we are out of symbols, so we add one to the next column and reset this one to zero
10
This 10 in hexidecimal is the same as writing 16 in decimal, because we counted 16 unique "things" to write it.
I hope this shows you how to write decimal 10 in hexidecimal now!
Rob
[ January 19, 2002: Message edited by: Rob Ross ]