Here we go! We're going to add 2221 and 2107 together.

Step 1: We'll start by adding the digits 1 & 7 in column 1 and get 8.

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

Step 3: We'll start by adding the digits 2 & 1 in column 3 and get 3.

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

So, 2221 + 2107 = 4328.

