We are presented with 5807 and 2091. Let's work out the sum.

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 0 & 9 in column 2 and get 9.

Step 3: We'll start by adding the digits 8 & 0 in column 3 and get 8.

Step 4: We'll start by adding the digits 5 & 2 in column 4 and get 7.

So, 5807 + 2091 = 7898.

