Okay, we are tasked with adding 913613 and 334624135. Let's begin!

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 1 & 3 in column 2 and get 4.

Step 3: We'll start by adding the digits 6 & 1 in column 3 and get 7.

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

Step 5: We'll start by adding the digits 1 & 2 in column 5 and get 3.

Step 6: We'll start by adding the digits 9 & 6 in column 6 and get 15.
We'll write down the last digit 5 and carry the 1 to the next column.

Step 7: We'll start by adding the digits 0 & 4 in column 7 and get 5.

Step 8: We'll start by adding the digits 0 & 3 in column 8 and get 3.

Step 9: We'll start by adding the digits 0 & 3 in column 9 and get 3.

So, 913613 + 334624135 = 335537748.

