No problem, let's work through this together. We're starting with 4212 and 9340 and adding them all up.

Step 1: We'll start by adding the digits 2 & 0 in column 1 and get 2.

Step 2: We'll start by adding the digits 1 & 4 in column 2 and get 5.

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 4 & 9 in column 4 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

So, 4212 + 9340 = 13552.

