OK, let's crack this. We're given 0 and our task is to multiply it by 43. Essentially, we'll be adding 0 to itself 43 times.
Step 1: 0 + 0 = 0
Step 2: 0 + 0 = 0
Step 3: 0 + 0 = 0
Step 4: 0 + 0 = 0
Step 5: 0 + 0 = 0
Step 6: 0 + 0 = 0
Step 7: 0 + 0 = 0
Step 8: 0 + 0 = 0
Step 9: 0 + 0 = 0
Step 10: 0 + 0 = 0
Step 11: 0 + 0 = 0
Step 12: 0 + 0 = 0
Step 13: 0 + 0 = 0
Step 14: 0 + 0 = 0
Step 15: 0 + 0 = 0
Step 16: 0 + 0 = 0
Step 17: 0 + 0 = 0
Step 18: 0 + 0 = 0
Step 19: 0 + 0 = 0
Step 20: 0 + 0 = 0
Step 21: 0 + 0 = 0
Step 22: 0 + 0 = 0
Step 23: 0 + 0 = 0
Step 24: 0 + 0 = 0
Step 25: 0 + 0 = 0
Step 26: 0 + 0 = 0
Step 27: 0 + 0 = 0
Step 28: 0 + 0 = 0
Step 29: 0 + 0 = 0
Step 30: 0 + 0 = 0
Step 31: 0 + 0 = 0
Step 32: 0 + 0 = 0
Step 33: 0 + 0 = 0
Step 34: 0 + 0 = 0
Step 35: 0 + 0 = 0
Step 36: 0 + 0 = 0
Step 37: 0 + 0 = 0
Step 38: 0 + 0 = 0
Step 39: 0 + 0 = 0
Step 40: 0 + 0 = 0
Step 41: 0 + 0 = 0
Step 42: 0 + 0 = 0
Step 43: 0 + 0 = 0

So, 0*43 = 0