We've got two numbers: 306 and 29. Let's find their sum.

Step 1: We'll start by adding the digits 6 & 9 in column 1 and get 15.
We'll write down the last digit 5 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 0 & 2 in column 2 and get 3.

Step 3: We'll start by adding the digits 3 & 0 in column 3 and get 3.

So, 306 + 29 = 335.

