Okay, we are given 1211 and 266. Let's add them up step by step.

Step 1: We'll start by adding the digits 1 & 6 in column 1 and get 7.

Step 2: We'll start by adding the digits 1 & 6 in column 2 and get 7.

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

Step 4: We'll start by adding the digits 1 & 0 in column 4 and get 1.

So, 1211 + 266 = 1477.

