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Binary to Decimal
Decimal is the number system we are used to working with and is base 10, with 10 digits from 0 to 9. Binary is a base 2 number system with just two digits - 0 and 1.
Take the number 11 (Decimal). How do we convert it into Binary?
Step 1:
Write out the following grid of numbers. Note that it starts (from the right hand side, with 1, and then each number is doubled)
| 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 |
Step 2:
Consider which numbers in the grid would add up to 11. In this case 8 + 2 + 1. Put a 1 under each of those numbers and a zero in every other cell.
| 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 |
| 0 | 0 | 0 | 0 | 1 | 0 | 1 | 1 |
Step 3:
Copy out the binary sequence. The below binary sequence is 11
| 0 | 0 | 0 | 0 | 1 | 0 | 1 | 1 |
The reverse is done to convert Binary to Decimal. Take the binary number, place it under the relevant headings, and look for the 1s. Add up the relevant place headings.