The base-4 method of counting in which only the digits 0, 1, 2, and 3 are used. The illustration above shows the numbers 0 to 63 represented in quaternary, and the following table gives the quaternary equivalents of the first few decimal numbers.
| 1 |
1 |
11 |
23 |
21 |
111 |
| 2 |
2 |
12 |
30 |
22 |
112 |
| 3 |
3 |
13 |
31 |
23 |
113 |
| 4 |
10 |
14 |
32 |
24 |
120 |
| 5 |
11 |
15 |
33 |
25 |
121 |
| 6 |
12 |
16 |
100 |
26 |
122 |
| 7 |
13 |
17 |
101 |
27 |
123 |
| 8 |
20 |
18 |
102 |
28 |
130 |
| 9 |
21 |
19 |
103 |
29 |
131 |
| 10 |
22 |
20 |
110 |
30 |
132 |
These digits have the following multiplication table.
 |
0 |
1 |
2 |
3 |
| 0 |
0 |
0 |
0 |
0 |
| 1 |
0 |
1 |
2 |
3 |
| 2 |
0 |
2 |
10 |
12 |
| 3 |
0 |
3 |
12 |
21 |
