Here we go! We're going to add 3547 and 6451 together.

Step 1: We'll start by adding the digits 7 & 1 in column 1 and get 8.

Step 2: We'll start by adding the digits 4 & 5 in column 2 and get 9.

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

Step 4: We'll start by adding the digits 3 & 6 in column 4 and get 9.

So, 3547 + 6451 = 9998.

