We are presented with 1124 and 5575. Let's work out the sum.

Step 1: We'll start by adding the digits 4 & 5 in column 1 and get 9.

Step 2: We'll start by adding the digits 2 & 7 in column 2 and get 9.

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

Step 4: We'll start by adding the digits 1 & 5 in column 4 and get 6.

So, 1124 + 5575 = 6699.

