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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

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