Alright, let's solve this math problem step by step. First, we have the number 403. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 87. So, we're going to take the number 403 and add it to itself 87 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
Step 46: 18135 + 403 = 18538
Step 47: 18538 + 403 = 18941
Step 48: 18941 + 403 = 19344
Step 49: 19344 + 403 = 19747
Step 50: 19747 + 403 = 20150
Step 51: 20150 + 403 = 20553
Step 52: 20553 + 403 = 20956
Step 53: 20956 + 403 = 21359
Step 54: 21359 + 403 = 21762
Step 55: 21762 + 403 = 22165
Step 56: 22165 + 403 = 22568
Step 57: 22568 + 403 = 22971
Step 58: 22971 + 403 = 23374
Step 59: 23374 + 403 = 23777
Step 60: 23777 + 403 = 24180
Step 61: 24180 + 403 = 24583
Step 62: 24583 + 403 = 24986
Step 63: 24986 + 403 = 25389
Step 64: 25389 + 403 = 25792
Step 65: 25792 + 403 = 26195
Step 66: 26195 + 403 = 26598
Step 67: 26598 + 403 = 27001
Step 68: 27001 + 403 = 27404
Step 69: 27404 + 403 = 27807
Step 70: 27807 + 403 = 28210
Step 71: 28210 + 403 = 28613
Step 72: 28613 + 403 = 29016
Step 73: 29016 + 403 = 29419
Step 74: 29419 + 403 = 29822
Step 75: 29822 + 403 = 30225
Step 76: 30225 + 403 = 30628
Step 77: 30628 + 403 = 31031
Step 78: 31031 + 403 = 31434
Step 79: 31434 + 403 = 31837
Step 80: 31837 + 403 = 32240
Step 81: 32240 + 403 = 32643
Step 82: 32643 + 403 = 33046
Step 83: 33046 + 403 = 33449
Step 84: 33449 + 403 = 33852
Step 85: 33852 + 403 = 34255
Step 86: 34255 + 403 = 34658
Step 87: 34658 + 403 = 35061

So, 403*87 = 35061