We are presented with 2430 and 1569. Let's work out the sum.

Step 1: We'll start by adding the digits 0 & 9 in column 1 and get 9.

Step 2: We'll start by adding the digits 3 & 6 in column 2 and get 9.

Step 3: We'll start by adding the digits 4 & 5 in column 3 and get 9.

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

So, 2430 + 1569 = 3999.

