We are presented with 3706 and 4143. Let's work out the sum.

Step 1: We'll start by adding the digits 6 & 3 in column 1 and get 9.

Step 2: We'll start by adding the digits 0 & 4 in column 2 and get 4.

Step 3: We'll start by adding the digits 7 & 1 in column 3 and get 8.

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

So, 3706 + 4143 = 7849.

