Here we go! We're going to add 7420 and 555 together.

Step 1: We'll start by adding the digits 0 & 5 in column 1 and get 5.

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 & 5 in column 3 and get 9.

Step 4: We'll start by adding the digits 7 & 0 in column 4 and get 7.

So, 7420 + 555 = 7975.

