Let's solve this addition problem. We have 5943 and 3505, and we need to add them together.

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 4 & 0 in column 2 and get 4.

Step 3: We'll start by adding the digits 9 & 5 in column 3 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 5 & 3 in column 4 and get 9.

So, 5943 + 3505 = 9448.

