OK, let's work through this together. We're starting with 402 and we're going to multiply it by 71, which means we add 402 to itself 71 times.
Step 1: 0 + 402 = 402
Step 2: 402 + 402 = 804
Step 3: 804 + 402 = 1206
Step 4: 1206 + 402 = 1608
Step 5: 1608 + 402 = 2010
Step 6: 2010 + 402 = 2412
Step 7: 2412 + 402 = 2814
Step 8: 2814 + 402 = 3216
Step 9: 3216 + 402 = 3618
Step 10: 3618 + 402 = 4020
Step 11: 4020 + 402 = 4422
Step 12: 4422 + 402 = 4824
Step 13: 4824 + 402 = 5226
Step 14: 5226 + 402 = 5628
Step 15: 5628 + 402 = 6030
Step 16: 6030 + 402 = 6432
Step 17: 6432 + 402 = 6834
Step 18: 6834 + 402 = 7236
Step 19: 7236 + 402 = 7638
Step 20: 7638 + 402 = 8040
Step 21: 8040 + 402 = 8442
Step 22: 8442 + 402 = 8844
Step 23: 8844 + 402 = 9246
Step 24: 9246 + 402 = 9648
Step 25: 9648 + 402 = 10050
Step 26: 10050 + 402 = 10452
Step 27: 10452 + 402 = 10854
Step 28: 10854 + 402 = 11256
Step 29: 11256 + 402 = 11658
Step 30: 11658 + 402 = 12060
Step 31: 12060 + 402 = 12462
Step 32: 12462 + 402 = 12864
Step 33: 12864 + 402 = 13266
Step 34: 13266 + 402 = 13668
Step 35: 13668 + 402 = 14070
Step 36: 14070 + 402 = 14472
Step 37: 14472 + 402 = 14874
Step 38: 14874 + 402 = 15276
Step 39: 15276 + 402 = 15678
Step 40: 15678 + 402 = 16080
Step 41: 16080 + 402 = 16482
Step 42: 16482 + 402 = 16884
Step 43: 16884 + 402 = 17286
Step 44: 17286 + 402 = 17688
Step 45: 17688 + 402 = 18090
Step 46: 18090 + 402 = 18492
Step 47: 18492 + 402 = 18894
Step 48: 18894 + 402 = 19296
Step 49: 19296 + 402 = 19698
Step 50: 19698 + 402 = 20100
Step 51: 20100 + 402 = 20502
Step 52: 20502 + 402 = 20904
Step 53: 20904 + 402 = 21306
Step 54: 21306 + 402 = 21708
Step 55: 21708 + 402 = 22110
Step 56: 22110 + 402 = 22512
Step 57: 22512 + 402 = 22914
Step 58: 22914 + 402 = 23316
Step 59: 23316 + 402 = 23718
Step 60: 23718 + 402 = 24120
Step 61: 24120 + 402 = 24522
Step 62: 24522 + 402 = 24924
Step 63: 24924 + 402 = 25326
Step 64: 25326 + 402 = 25728
Step 65: 25728 + 402 = 26130
Step 66: 26130 + 402 = 26532
Step 67: 26532 + 402 = 26934
Step 68: 26934 + 402 = 27336
Step 69: 27336 + 402 = 27738
Step 70: 27738 + 402 = 28140
Step 71: 28140 + 402 = 28542

So, 402*71 = 28542