We have numbers 1023 and 2401. Let's start adding them together.

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

Step 2: We'll start by adding the digits 2 & 0 in column 2 and get 2.

Step 3: We'll start by adding the digits 0 & 4 in column 3 and get 4.

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

So, 1023 + 2401 = 3424.

