We have numbers 3059 and 643. Let's start adding them together.

Step 1: We'll start by adding the digits 9 & 3 in column 1 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 5 & 4 in column 2 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 0 & 6 in column 3 and get 7.

Step 4: We'll start by adding the digits 3 & 0 in column 4 and get 3.

So, 3059 + 643 = 3702.

