We are presented with 1583 and 1105. Let's work out the sum.

Step 1: We'll start by adding the digits 3 & 5 in column 1 and get 8.

Step 2: We'll start by adding the digits 8 & 0 in column 2 and get 8.

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

Step 4: We'll start by adding the digits 1 & 1 in column 4 and get 2.

So, 1583 + 1105 = 2688.

