Let's get this math done. We have 631 and we're going to multiply it by 3. This is the same as taking 631 and adding it to itself 3 times.
Step 1: 0 + 631 = 631
Step 2: 631 + 631 = 1262
Step 3: 1262 + 631 = 1893

So, 631*3 = 1893