Alright, let's solve this math problem step by step. First, we have the number 684. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 6. So, we're going to take the number 684 and add it to itself 6 times.
Step 1: 0 + 684 = 684
Step 2: 684 + 684 = 1368
Step 3: 1368 + 684 = 2052
Step 4: 2052 + 684 = 2736
Step 5: 2736 + 684 = 3420
Step 6: 3420 + 684 = 4104

So, 684*6 = 4104