Here we go! We're going to add 9407 and 3030 together.

Step 1: We'll start by adding the digits 7 & 0 in column 1 and get 7.

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

Step 3: We'll start by adding the digits 4 & 0 in column 3 and get 4.

Step 4: We'll start by adding the digits 9 & 3 in column 4 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

So, 9407 + 3030 = 12437.

