Let's roll up our sleeves and solve this. We have 684 and we're going to multiply it by 3, essentially adding 684 to itself 3 times.
Step 1: 0 + 684 = 684
Step 2: 684 + 684 = 1368
Step 3: 1368 + 684 = 2052

So, 684*3 = 2052