1002 = 4 — binary 100 equals decimal 4.
Each bit is multiplied by its place value (right to left: 1, 2, 4, 8, ...) and the results are added:
1 × 4 = 4
So binary 100 = decimal 4. You can verify any value with the binary to decimal converter.
| Binary | Decimal |
|---|---|
| 100 | 4 |
| 101 | 5 |
| 110 | 6 |
| 111 | 7 |
| 1000 | 8 |
| 1010 | 10 |
| 1101 | 13 |
| 1111 | 15 |
| 10000 | 16 |
| 11010 | 26 |
100 in binary equals <b>4</b> in decimal. Add the place values of every bit set to 1: 1 × 4 = 4.
Write the place values above each bit from right to left (1, 2, 4, 8, 16, ...), multiply each bit by its place value, then add all the results.
Yes — a binary number only uses the digits 0 and 1, and every digit in 100 is valid.