Let's solve this addition problem. We have 345 and 9431, and we need to add them together.

Step 1: We'll start by adding the digits 5 & 1 in column 1 and get 6.

Step 2: We'll start by adding the digits 4 & 3 in column 2 and get 7.

Step 3: We'll start by adding the digits 3 & 4 in column 3 and get 7.

Step 4: We'll start by adding the digits 0 & 9 in column 4 and get 9.

So, 345 + 9431 = 9776.

