Sure thing, let's get straight to it. We start with 403 and we're going to multiply it by 45, which means adding 403 to itself 45 times.
Step 1: 0 + 403 = 403
Step 2: 403 + 403 = 806
Step 3: 806 + 403 = 1209
Step 4: 1209 + 403 = 1612
Step 5: 1612 + 403 = 2015
Step 6: 2015 + 403 = 2418
Step 7: 2418 + 403 = 2821
Step 8: 2821 + 403 = 3224
Step 9: 3224 + 403 = 3627
Step 10: 3627 + 403 = 4030
Step 11: 4030 + 403 = 4433
Step 12: 4433 + 403 = 4836
Step 13: 4836 + 403 = 5239
Step 14: 5239 + 403 = 5642
Step 15: 5642 + 403 = 6045
Step 16: 6045 + 403 = 6448
Step 17: 6448 + 403 = 6851
Step 18: 6851 + 403 = 7254
Step 19: 7254 + 403 = 7657
Step 20: 7657 + 403 = 8060
Step 21: 8060 + 403 = 8463
Step 22: 8463 + 403 = 8866
Step 23: 8866 + 403 = 9269
Step 24: 9269 + 403 = 9672
Step 25: 9672 + 403 = 10075
Step 26: 10075 + 403 = 10478
Step 27: 10478 + 403 = 10881
Step 28: 10881 + 403 = 11284
Step 29: 11284 + 403 = 11687
Step 30: 11687 + 403 = 12090
Step 31: 12090 + 403 = 12493
Step 32: 12493 + 403 = 12896
Step 33: 12896 + 403 = 13299
Step 34: 13299 + 403 = 13702
Step 35: 13702 + 403 = 14105
Step 36: 14105 + 403 = 14508
Step 37: 14508 + 403 = 14911
Step 38: 14911 + 403 = 15314
Step 39: 15314 + 403 = 15717
Step 40: 15717 + 403 = 16120
Step 41: 16120 + 403 = 16523
Step 42: 16523 + 403 = 16926
Step 43: 16926 + 403 = 17329
Step 44: 17329 + 403 = 17732
Step 45: 17732 + 403 = 18135

So, 403*45 = 18135