Adding numbers in base 2, also known as binary addition, follows similar principles to adding numbers in base 10 (decimal). In binary, there are only two digits: 0 and 1. When adding binary numbers, you perform addition column by column, carrying over any excess 1 to the next column, just like in decimal addition.
Let’s go through an example of adding two binary numbers: 1101 (13 in decimal) and 101 (5 in decimal):
 
1 1 0 1 (1101)
+ 1 0 1 ( 101)
—————
1 0 0 1 0 (10010)
 

Here’s the step-by-step breakdown:

1. Start from the rightmost column (the least significant bit) and move to the left.
2. Add the digits in each column along with any carry from the previous column.
   • 1 + 1 = 0 (with a carry of 1)
   • 0 + 0 + 1 = 1 (no carry)
   • 1 + 1 + 0 = 0 (with a carry of 1)
   • 1 + 0 + 1 = 0 (with a carry of 1)
3. In the final result, if there’s a carry left after adding the leftmost columns, add it as an additional leftmost digit.

The result is 10010, which is 18 in decimal.
Remember that binary addition is straightforward once you understand the concept. Just add each column, carry over as necessary, and write down the result.