Here we go! We're going to add 221 and 7420 together.

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

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

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

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

So, 221 + 7420 = 7641.

