We are presented with 1121 and 7107. Let's work out the sum.

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 1 & 1 in column 3 and get 2.

Step 4: We'll start by adding the digits 1 & 7 in column 4 and get 8.

So, 1121 + 7107 = 8228.

