We have numbers 210 and 2345. Let's start adding them together.

Step 1: We'll start by adding the digits 0 & 5 in column 1 and get 5.

Step 2: We'll start by adding the digits 1 & 4 in column 2 and get 5.

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

Step 4: We'll start by adding the digits 0 & 2 in column 4 and get 2.

So, 210 + 2345 = 2555.

