Not to worry, we've got 5420 and 2379. Let's get to adding them!

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 2 & 7 in column 2 and get 9.

Step 3: We'll start by adding the digits 4 & 3 in column 3 and get 7.

Step 4: We'll start by adding the digits 5 & 2 in column 4 and get 7.

So, 5420 + 2379 = 7799.

