OK, let's do this. We've got 130 and 513 and we're adding them all together.

Step 1: We'll start by adding the digits 0 & 3 in column 1 and get 3.

Step 2: We'll start by adding the digits 3 & 1 in column 2 and get 4.

Step 3: We'll start by adding the digits 1 & 5 in column 3 and get 6.

So, 130 + 513 = 643.

