Here we go! We're going to add 3345 and 3100 together.

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

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 3 & 1 in column 3 and get 4.

Step 4: We'll start by adding the digits 3 & 3 in column 4 and get 6.

So, 3345 + 3100 = 6445.

