We have numbers 242 and 1398. Let's start adding them together.

Step 1: We'll start by adding the digits 2 & 8 in column 1 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 4 & 9 in column 2 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 2 & 3 in column 3 and get 6.

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

So, 242 + 1398 = 1640.

