Not to worry, we've got 7420 and 5153. Let's get to adding them!

Step 1: We'll start by adding the digits 0 & 3 in column 1 and get 3.

Step 2: We'll start by adding the digits 2 & 5 in column 2 and get 7.

Step 3: We'll start by adding the digits 4 & 1 in column 3 and get 5.

Step 4: We'll start by adding the digits 7 & 5 in column 4 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

So, 7420 + 5153 = 12573.

