Okay, we are tasked with adding 113 and 1242. Let's begin!

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

Step 2: We'll start by adding the digits 1 & 4 in column 2 and get 5.

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

Step 4: We'll start by adding the digits 0 & 1 in column 4 and get 1.

So, 113 + 1242 = 1355.

