Let's get this math done. We have 504 and we're going to multiply it by 161. This is the same as taking 504 and adding it to itself 161 times.
Step 1: 0 + 504 = 504
Step 2: 504 + 504 = 1008
Step 3: 1008 + 504 = 1512
Step 4: 1512 + 504 = 2016
Step 5: 2016 + 504 = 2520
Step 6: 2520 + 504 = 3024
Step 7: 3024 + 504 = 3528
Step 8: 3528 + 504 = 4032
Step 9: 4032 + 504 = 4536
Step 10: 4536 + 504 = 5040
Step 11: 5040 + 504 = 5544
Step 12: 5544 + 504 = 6048
Step 13: 6048 + 504 = 6552
Step 14: 6552 + 504 = 7056
Step 15: 7056 + 504 = 7560
Step 16: 7560 + 504 = 8064
Step 17: 8064 + 504 = 8568
Step 18: 8568 + 504 = 9072
Step 19: 9072 + 504 = 9576
Step 20: 9576 + 504 = 10080
Step 21: 10080 + 504 = 10584
Step 22: 10584 + 504 = 11088
Step 23: 11088 + 504 = 11592
Step 24: 11592 + 504 = 12096
Step 25: 12096 + 504 = 12600
Step 26: 12600 + 504 = 13104
Step 27: 13104 + 504 = 13608
Step 28: 13608 + 504 = 14112
Step 29: 14112 + 504 = 14616
Step 30: 14616 + 504 = 15120
Step 31: 15120 + 504 = 15624
Step 32: 15624 + 504 = 16128
Step 33: 16128 + 504 = 16632
Step 34: 16632 + 504 = 17136
Step 35: 17136 + 504 = 17640
Step 36: 17640 + 504 = 18144
Step 37: 18144 + 504 = 18648
Step 38: 18648 + 504 = 19152
Step 39: 19152 + 504 = 19656
Step 40: 19656 + 504 = 20160
Step 41: 20160 + 504 = 20664
Step 42: 20664 + 504 = 21168
Step 43: 21168 + 504 = 21672
Step 44: 21672 + 504 = 22176
Step 45: 22176 + 504 = 22680
Step 46: 22680 + 504 = 23184
Step 47: 23184 + 504 = 23688
Step 48: 23688 + 504 = 24192
Step 49: 24192 + 504 = 24696
Step 50: 24696 + 504 = 25200
Step 51: 25200 + 504 = 25704
Step 52: 25704 + 504 = 26208
Step 53: 26208 + 504 = 26712
Step 54: 26712 + 504 = 27216
Step 55: 27216 + 504 = 27720
Step 56: 27720 + 504 = 28224
Step 57: 28224 + 504 = 28728
Step 58: 28728 + 504 = 29232
Step 59: 29232 + 504 = 29736
Step 60: 29736 + 504 = 30240
Step 61: 30240 + 504 = 30744
Step 62: 30744 + 504 = 31248
Step 63: 31248 + 504 = 31752
Step 64: 31752 + 504 = 32256
Step 65: 32256 + 504 = 32760
Step 66: 32760 + 504 = 33264
Step 67: 33264 + 504 = 33768
Step 68: 33768 + 504 = 34272
Step 69: 34272 + 504 = 34776
Step 70: 34776 + 504 = 35280
Step 71: 35280 + 504 = 35784
Step 72: 35784 + 504 = 36288
Step 73: 36288 + 504 = 36792
Step 74: 36792 + 504 = 37296
Step 75: 37296 + 504 = 37800
Step 76: 37800 + 504 = 38304
Step 77: 38304 + 504 = 38808
Step 78: 38808 + 504 = 39312
Step 79: 39312 + 504 = 39816
Step 80: 39816 + 504 = 40320
Step 81: 40320 + 504 = 40824
Step 82: 40824 + 504 = 41328
Step 83: 41328 + 504 = 41832
Step 84: 41832 + 504 = 42336
Step 85: 42336 + 504 = 42840
Step 86: 42840 + 504 = 43344
Step 87: 43344 + 504 = 43848
Step 88: 43848 + 504 = 44352
Step 89: 44352 + 504 = 44856
Step 90: 44856 + 504 = 45360
Step 91: 45360 + 504 = 45864
Step 92: 45864 + 504 = 46368
Step 93: 46368 + 504 = 46872
Step 94: 46872 + 504 = 47376
Step 95: 47376 + 504 = 47880
Step 96: 47880 + 504 = 48384
Step 97: 48384 + 504 = 48888
Step 98: 48888 + 504 = 49392
Step 99: 49392 + 504 = 49896
Step 100: 49896 + 504 = 50400
Step 101: 50400 + 504 = 50904
Step 102: 50904 + 504 = 51408
Step 103: 51408 + 504 = 51912
Step 104: 51912 + 504 = 52416
Step 105: 52416 + 504 = 52920
Step 106: 52920 + 504 = 53424
Step 107: 53424 + 504 = 53928
Step 108: 53928 + 504 = 54432
Step 109: 54432 + 504 = 54936
Step 110: 54936 + 504 = 55440
Step 111: 55440 + 504 = 55944
Step 112: 55944 + 504 = 56448
Step 113: 56448 + 504 = 56952
Step 114: 56952 + 504 = 57456
Step 115: 57456 + 504 = 57960
Step 116: 57960 + 504 = 58464
Step 117: 58464 + 504 = 58968
Step 118: 58968 + 504 = 59472
Step 119: 59472 + 504 = 59976
Step 120: 59976 + 504 = 60480
Step 121: 60480 + 504 = 60984
Step 122: 60984 + 504 = 61488
Step 123: 61488 + 504 = 61992
Step 124: 61992 + 504 = 62496
Step 125: 62496 + 504 = 63000
Step 126: 63000 + 504 = 63504
Step 127: 63504 + 504 = 64008
Step 128: 64008 + 504 = 64512
Step 129: 64512 + 504 = 65016
Step 130: 65016 + 504 = 65520
Step 131: 65520 + 504 = 66024
Step 132: 66024 + 504 = 66528
Step 133: 66528 + 504 = 67032
Step 134: 67032 + 504 = 67536
Step 135: 67536 + 504 = 68040
Step 136: 68040 + 504 = 68544
Step 137: 68544 + 504 = 69048
Step 138: 69048 + 504 = 69552
Step 139: 69552 + 504 = 70056
Step 140: 70056 + 504 = 70560
Step 141: 70560 + 504 = 71064
Step 142: 71064 + 504 = 71568
Step 143: 71568 + 504 = 72072
Step 144: 72072 + 504 = 72576
Step 145: 72576 + 504 = 73080
Step 146: 73080 + 504 = 73584
Step 147: 73584 + 504 = 74088
Step 148: 74088 + 504 = 74592
Step 149: 74592 + 504 = 75096
Step 150: 75096 + 504 = 75600
Step 151: 75600 + 504 = 76104
Step 152: 76104 + 504 = 76608
Step 153: 76608 + 504 = 77112
Step 154: 77112 + 504 = 77616
Step 155: 77616 + 504 = 78120
Step 156: 78120 + 504 = 78624
Step 157: 78624 + 504 = 79128
Step 158: 79128 + 504 = 79632
Step 159: 79632 + 504 = 80136
Step 160: 80136 + 504 = 80640
Step 161: 80640 + 504 = 81144

So, 504*161 = 81144