Sure thing! We've got 789 and we're gonna multiply it by 30. That's the same as adding 789 to itself 30 times.
Step 1: 0 + 789 = 789
Step 2: 789 + 789 = 1578
Step 3: 1578 + 789 = 2367
Step 4: 2367 + 789 = 3156
Step 5: 3156 + 789 = 3945
Step 6: 3945 + 789 = 4734
Step 7: 4734 + 789 = 5523
Step 8: 5523 + 789 = 6312
Step 9: 6312 + 789 = 7101
Step 10: 7101 + 789 = 7890
Step 11: 7890 + 789 = 8679
Step 12: 8679 + 789 = 9468
Step 13: 9468 + 789 = 10257
Step 14: 10257 + 789 = 11046
Step 15: 11046 + 789 = 11835
Step 16: 11835 + 789 = 12624
Step 17: 12624 + 789 = 13413
Step 18: 13413 + 789 = 14202
Step 19: 14202 + 789 = 14991
Step 20: 14991 + 789 = 15780
Step 21: 15780 + 789 = 16569
Step 22: 16569 + 789 = 17358
Step 23: 17358 + 789 = 18147
Step 24: 18147 + 789 = 18936
Step 25: 18936 + 789 = 19725
Step 26: 19725 + 789 = 20514
Step 27: 20514 + 789 = 21303
Step 28: 21303 + 789 = 22092
Step 29: 22092 + 789 = 22881
Step 30: 22881 + 789 = 23670

So, 789*30 = 23670