We are presented with 3427 and 5290. Let's work out the sum.

Step 1: We'll start by adding the digits 7 & 0 in column 1 and get 7.

Step 2: We'll start by adding the digits 2 & 9 in column 2 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 4 & 2 in column 3 and get 7.

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

So, 3427 + 5290 = 8717.

