We are presented with 3549 and 1749. Let's work out the sum.

Step 1: We'll start by adding the digits 9 & 9 in column 1 and get 18.
We'll write down the last digit 8 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 4 & 4 in column 2 and get 9.

Step 3: We'll start by adding the digits 5 & 7 in column 3 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 3 & 1 in column 4 and get 5.

So, 3549 + 1749 = 5298.

