Let's solve this addition problem. We have 1211 and 3377, and we need to add them 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 1 & 7 in column 2 and get 8.

Step 3: We'll start by adding the digits 2 & 3 in column 3 and get 5.

Step 4: We'll start by adding the digits 1 & 3 in column 4 and get 4.

So, 1211 + 3377 = 4588.

