Alright, let's solve this math problem step by step. First, we have the number 615. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 210. So, we're going to take the number 615 and add it to itself 210 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
Step 146: 89175 + 615 = 89790
Step 147: 89790 + 615 = 90405
Step 148: 90405 + 615 = 91020
Step 149: 91020 + 615 = 91635
Step 150: 91635 + 615 = 92250
Step 151: 92250 + 615 = 92865
Step 152: 92865 + 615 = 93480
Step 153: 93480 + 615 = 94095
Step 154: 94095 + 615 = 94710
Step 155: 94710 + 615 = 95325
Step 156: 95325 + 615 = 95940
Step 157: 95940 + 615 = 96555
Step 158: 96555 + 615 = 97170
Step 159: 97170 + 615 = 97785
Step 160: 97785 + 615 = 98400
Step 161: 98400 + 615 = 99015
Step 162: 99015 + 615 = 99630
Step 163: 99630 + 615 = 100245
Step 164: 100245 + 615 = 100860
Step 165: 100860 + 615 = 101475
Step 166: 101475 + 615 = 102090
Step 167: 102090 + 615 = 102705
Step 168: 102705 + 615 = 103320
Step 169: 103320 + 615 = 103935
Step 170: 103935 + 615 = 104550
Step 171: 104550 + 615 = 105165
Step 172: 105165 + 615 = 105780
Step 173: 105780 + 615 = 106395
Step 174: 106395 + 615 = 107010
Step 175: 107010 + 615 = 107625
Step 176: 107625 + 615 = 108240
Step 177: 108240 + 615 = 108855
Step 178: 108855 + 615 = 109470
Step 179: 109470 + 615 = 110085
Step 180: 110085 + 615 = 110700
Step 181: 110700 + 615 = 111315
Step 182: 111315 + 615 = 111930
Step 183: 111930 + 615 = 112545
Step 184: 112545 + 615 = 113160
Step 185: 113160 + 615 = 113775
Step 186: 113775 + 615 = 114390
Step 187: 114390 + 615 = 115005
Step 188: 115005 + 615 = 115620
Step 189: 115620 + 615 = 116235
Step 190: 116235 + 615 = 116850
Step 191: 116850 + 615 = 117465
Step 192: 117465 + 615 = 118080
Step 193: 118080 + 615 = 118695
Step 194: 118695 + 615 = 119310
Step 195: 119310 + 615 = 119925
Step 196: 119925 + 615 = 120540
Step 197: 120540 + 615 = 121155
Step 198: 121155 + 615 = 121770
Step 199: 121770 + 615 = 122385
Step 200: 122385 + 615 = 123000
Step 201: 123000 + 615 = 123615
Step 202: 123615 + 615 = 124230
Step 203: 124230 + 615 = 124845
Step 204: 124845 + 615 = 125460
Step 205: 125460 + 615 = 126075
Step 206: 126075 + 615 = 126690
Step 207: 126690 + 615 = 127305
Step 208: 127305 + 615 = 127920
Step 209: 127920 + 615 = 128535
Step 210: 128535 + 615 = 129150

So, 615*210 = 129150