We are presented with 1000 and 8685. Let's work out the sum.

Step 1: We'll start by adding the digits 0 & 5 in column 1 and get 5.

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

Step 3: We'll start by adding the digits 0 & 6 in column 3 and get 6.

Step 4: We'll start by adding the digits 1 & 8 in column 4 and get 9.

So, 1000 + 8685 = 9685.

