We have numbers 5406 and 3566. Let's start adding them together.

Step 1: We'll start by adding the digits 6 & 6 in column 1 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 0 & 6 in column 2 and get 7.

Step 3: We'll start by adding the digits 4 & 5 in column 3 and get 9.

Step 4: We'll start by adding the digits 5 & 3 in column 4 and get 8.

So, 5406 + 3566 = 8972.

