Hexadecimal Numbers

Hexadecimal numbers are numbers represented in base 16 , which means the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F instead of just 0-9.

Just as in base 10, we have the 1s place, 10s place, 100s place, 1000s place, 10,000s place, etc. (the powers of 10), in base 16 we have the 1s place, 16s place, 256s place, 4096s place, etc. (the powers of 16).

In base 10, the number 13 means one group of 10 and 3 ones.  In base 16, the number 13 means one group of 16 and 3 ones.  (This would be equivalent to 19 in base 10.)

Below we count up to 32 in base 16:

BASE 16 BASE 10
0 0
1 1
2 2

3

 3
4 4
5 5
6 6
7 7
8 8
9 9
A 10
B 11
C 12
D 13
E 14
F 15
10 16
11 17
12 18
13 19
14 20
15 21
16 22
17 23
18 24
19 25
1A 26
1B 27
1C 28
1D 29
1E 30
1F 31
20 32

Hexadecimal numbers are used extensively in computer science.