We have numbers 1518 and 4206. Let's start adding them together.

Step 1: We'll start by adding the digits 8 & 6 in column 1 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 1 & 0 in column 2 and get 2.

Step 3: We'll start by adding the digits 5 & 2 in column 3 and get 7.

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

So, 1518 + 4206 = 5724.

