OK, let's work through this together. We're starting with 615 and we're going to multiply it by 145, which means we add 615 to itself 145 times.
Step 1: 0 + 615 = 615
Step 2: 615 + 615 = 1230
Step 3: 1230 + 615 = 1845
Step 4: 1845 + 615 = 2460
Step 5: 2460 + 615 = 3075
Step 6: 3075 + 615 = 3690
Step 7: 3690 + 615 = 4305
Step 8: 4305 + 615 = 4920
Step 9: 4920 + 615 = 5535
Step 10: 5535 + 615 = 6150
Step 11: 6150 + 615 = 6765
Step 12: 6765 + 615 = 7380
Step 13: 7380 + 615 = 7995
Step 14: 7995 + 615 = 8610
Step 15: 8610 + 615 = 9225
Step 16: 9225 + 615 = 9840
Step 17: 9840 + 615 = 10455
Step 18: 10455 + 615 = 11070
Step 19: 11070 + 615 = 11685
Step 20: 11685 + 615 = 12300
Step 21: 12300 + 615 = 12915
Step 22: 12915 + 615 = 13530
Step 23: 13530 + 615 = 14145
Step 24: 14145 + 615 = 14760
Step 25: 14760 + 615 = 15375
Step 26: 15375 + 615 = 15990
Step 27: 15990 + 615 = 16605
Step 28: 16605 + 615 = 17220
Step 29: 17220 + 615 = 17835
Step 30: 17835 + 615 = 18450
Step 31: 18450 + 615 = 19065
Step 32: 19065 + 615 = 19680
Step 33: 19680 + 615 = 20295
Step 34: 20295 + 615 = 20910
Step 35: 20910 + 615 = 21525
Step 36: 21525 + 615 = 22140
Step 37: 22140 + 615 = 22755
Step 38: 22755 + 615 = 23370
Step 39: 23370 + 615 = 23985
Step 40: 23985 + 615 = 24600
Step 41: 24600 + 615 = 25215
Step 42: 25215 + 615 = 25830
Step 43: 25830 + 615 = 26445
Step 44: 26445 + 615 = 27060
Step 45: 27060 + 615 = 27675
Step 46: 27675 + 615 = 28290
Step 47: 28290 + 615 = 28905
Step 48: 28905 + 615 = 29520
Step 49: 29520 + 615 = 30135
Step 50: 30135 + 615 = 30750
Step 51: 30750 + 615 = 31365
Step 52: 31365 + 615 = 31980
Step 53: 31980 + 615 = 32595
Step 54: 32595 + 615 = 33210
Step 55: 33210 + 615 = 33825
Step 56: 33825 + 615 = 34440
Step 57: 34440 + 615 = 35055
Step 58: 35055 + 615 = 35670
Step 59: 35670 + 615 = 36285
Step 60: 36285 + 615 = 36900
Step 61: 36900 + 615 = 37515
Step 62: 37515 + 615 = 38130
Step 63: 38130 + 615 = 38745
Step 64: 38745 + 615 = 39360
Step 65: 39360 + 615 = 39975
Step 66: 39975 + 615 = 40590
Step 67: 40590 + 615 = 41205
Step 68: 41205 + 615 = 41820
Step 69: 41820 + 615 = 42435
Step 70: 42435 + 615 = 43050
Step 71: 43050 + 615 = 43665
Step 72: 43665 + 615 = 44280
Step 73: 44280 + 615 = 44895
Step 74: 44895 + 615 = 45510
Step 75: 45510 + 615 = 46125
Step 76: 46125 + 615 = 46740
Step 77: 46740 + 615 = 47355
Step 78: 47355 + 615 = 47970
Step 79: 47970 + 615 = 48585
Step 80: 48585 + 615 = 49200
Step 81: 49200 + 615 = 49815
Step 82: 49815 + 615 = 50430
Step 83: 50430 + 615 = 51045
Step 84: 51045 + 615 = 51660
Step 85: 51660 + 615 = 52275
Step 86: 52275 + 615 = 52890
Step 87: 52890 + 615 = 53505
Step 88: 53505 + 615 = 54120
Step 89: 54120 + 615 = 54735
Step 90: 54735 + 615 = 55350
Step 91: 55350 + 615 = 55965
Step 92: 55965 + 615 = 56580
Step 93: 56580 + 615 = 57195
Step 94: 57195 + 615 = 57810
Step 95: 57810 + 615 = 58425
Step 96: 58425 + 615 = 59040
Step 97: 59040 + 615 = 59655
Step 98: 59655 + 615 = 60270
Step 99: 60270 + 615 = 60885
Step 100: 60885 + 615 = 61500
Step 101: 61500 + 615 = 62115
Step 102: 62115 + 615 = 62730
Step 103: 62730 + 615 = 63345
Step 104: 63345 + 615 = 63960
Step 105: 63960 + 615 = 64575
Step 106: 64575 + 615 = 65190
Step 107: 65190 + 615 = 65805
Step 108: 65805 + 615 = 66420
Step 109: 66420 + 615 = 67035
Step 110: 67035 + 615 = 67650
Step 111: 67650 + 615 = 68265
Step 112: 68265 + 615 = 68880
Step 113: 68880 + 615 = 69495
Step 114: 69495 + 615 = 70110
Step 115: 70110 + 615 = 70725
Step 116: 70725 + 615 = 71340
Step 117: 71340 + 615 = 71955
Step 118: 71955 + 615 = 72570
Step 119: 72570 + 615 = 73185
Step 120: 73185 + 615 = 73800
Step 121: 73800 + 615 = 74415
Step 122: 74415 + 615 = 75030
Step 123: 75030 + 615 = 75645
Step 124: 75645 + 615 = 76260
Step 125: 76260 + 615 = 76875
Step 126: 76875 + 615 = 77490
Step 127: 77490 + 615 = 78105
Step 128: 78105 + 615 = 78720
Step 129: 78720 + 615 = 79335
Step 130: 79335 + 615 = 79950
Step 131: 79950 + 615 = 80565
Step 132: 80565 + 615 = 81180
Step 133: 81180 + 615 = 81795
Step 134: 81795 + 615 = 82410
Step 135: 82410 + 615 = 83025
Step 136: 83025 + 615 = 83640
Step 137: 83640 + 615 = 84255
Step 138: 84255 + 615 = 84870
Step 139: 84870 + 615 = 85485
Step 140: 85485 + 615 = 86100
Step 141: 86100 + 615 = 86715
Step 142: 86715 + 615 = 87330
Step 143: 87330 + 615 = 87945
Step 144: 87945 + 615 = 88560
Step 145: 88560 + 615 = 89175

So, 615*145 = 89175