Okay, we are given 1569 and 3120. Let's add them up step by step.

Step 1: We'll start by adding the digits 9 & 0 in column 1 and get 9.

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

Step 3: We'll start by adding the digits 5 & 1 in column 3 and get 6.

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

So, 1569 + 3120 = 4689.

