Okay, we are given 4236 and 1403. Let's add them up step by step.

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 3 & 0 in column 2 and get 3.

Step 3: We'll start by adding the digits 2 & 4 in column 3 and get 6.

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

So, 4236 + 1403 = 5639.

