We are presented with 6213 and 3144. Let's work out the sum.

Step 1: We'll start by adding the digits 3 & 4 in column 1 and get 7.

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 & 1 in column 3 and get 3.

Step 4: We'll start by adding the digits 6 & 3 in column 4 and get 9.

So, 6213 + 3144 = 9357.

