We have numbers 1140 and 2121. Let's start adding them together.

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

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

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 & 2 in column 4 and get 3.

So, 1140 + 2121 = 3261.

