Alright, let's solve this problem step by step. We have 5859 and 1820 and we're adding them together.

Step 1: We'll start by adding the digits 9 & 0 in column 1 and get 9.

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

Step 3: We'll start by adding the digits 8 & 8 in column 3 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 5 & 1 in column 4 and get 7.

So, 5859 + 1820 = 7679.

