We are presented with 2126 and 3742. Let's work out the sum.

Step 1: We'll start by adding the digits 6 & 2 in column 1 and get 8.

Step 2: We'll start by adding the digits 2 & 4 in column 2 and get 6.

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

Step 4: We'll start by adding the digits 2 & 3 in column 4 and get 5.

So, 2126 + 3742 = 5868.

