Alright, let's solve this math problem step by step. First, we have the number 678. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 30. So, we're going to take the number 678 and add it to itself 30 times.
Step 1: 0 + 678 = 678
Step 2: 678 + 678 = 1356
Step 3: 1356 + 678 = 2034
Step 4: 2034 + 678 = 2712
Step 5: 2712 + 678 = 3390
Step 6: 3390 + 678 = 4068
Step 7: 4068 + 678 = 4746
Step 8: 4746 + 678 = 5424
Step 9: 5424 + 678 = 6102
Step 10: 6102 + 678 = 6780
Step 11: 6780 + 678 = 7458
Step 12: 7458 + 678 = 8136
Step 13: 8136 + 678 = 8814
Step 14: 8814 + 678 = 9492
Step 15: 9492 + 678 = 10170
Step 16: 10170 + 678 = 10848
Step 17: 10848 + 678 = 11526
Step 18: 11526 + 678 = 12204
Step 19: 12204 + 678 = 12882
Step 20: 12882 + 678 = 13560
Step 21: 13560 + 678 = 14238
Step 22: 14238 + 678 = 14916
Step 23: 14916 + 678 = 15594
Step 24: 15594 + 678 = 16272
Step 25: 16272 + 678 = 16950
Step 26: 16950 + 678 = 17628
Step 27: 17628 + 678 = 18306
Step 28: 18306 + 678 = 18984
Step 29: 18984 + 678 = 19662
Step 30: 19662 + 678 = 20340

So, 678*30 = 20340