Let's solve this addition problem. We have 246 and 407, and we need to add them together.

Step 1: We'll start by adding the digits 6 & 7 in column 1 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 4 & 0 in column 2 and get 5.

Step 3: We'll start by adding the digits 2 & 4 in column 3 and get 6.

So, 246 + 407 = 653.

