Okay, we are given 633 and 970. Let's add them up step by step.

Step 1: We'll start by adding the digits 3 & 0 in column 1 and get 3.

Step 2: We'll start by adding the digits 3 & 7 in column 2 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 6 & 9 in column 3 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

So, 633 + 970 = 1603.

