Alright, let's solve this math problem step by step. First, we have the number 687. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 187. So, we're going to take the number 687 and add it to itself 187 times.
Step 1: 0 + 687 = 687
Step 2: 687 + 687 = 1374
Step 3: 1374 + 687 = 2061
Step 4: 2061 + 687 = 2748
Step 5: 2748 + 687 = 3435
Step 6: 3435 + 687 = 4122
Step 7: 4122 + 687 = 4809
Step 8: 4809 + 687 = 5496
Step 9: 5496 + 687 = 6183
Step 10: 6183 + 687 = 6870
Step 11: 6870 + 687 = 7557
Step 12: 7557 + 687 = 8244
Step 13: 8244 + 687 = 8931
Step 14: 8931 + 687 = 9618
Step 15: 9618 + 687 = 10305
Step 16: 10305 + 687 = 10992
Step 17: 10992 + 687 = 11679
Step 18: 11679 + 687 = 12366
Step 19: 12366 + 687 = 13053
Step 20: 13053 + 687 = 13740
Step 21: 13740 + 687 = 14427
Step 22: 14427 + 687 = 15114
Step 23: 15114 + 687 = 15801
Step 24: 15801 + 687 = 16488
Step 25: 16488 + 687 = 17175
Step 26: 17175 + 687 = 17862
Step 27: 17862 + 687 = 18549
Step 28: 18549 + 687 = 19236
Step 29: 19236 + 687 = 19923
Step 30: 19923 + 687 = 20610
Step 31: 20610 + 687 = 21297
Step 32: 21297 + 687 = 21984
Step 33: 21984 + 687 = 22671
Step 34: 22671 + 687 = 23358
Step 35: 23358 + 687 = 24045
Step 36: 24045 + 687 = 24732
Step 37: 24732 + 687 = 25419
Step 38: 25419 + 687 = 26106
Step 39: 26106 + 687 = 26793
Step 40: 26793 + 687 = 27480
Step 41: 27480 + 687 = 28167
Step 42: 28167 + 687 = 28854
Step 43: 28854 + 687 = 29541
Step 44: 29541 + 687 = 30228
Step 45: 30228 + 687 = 30915
Step 46: 30915 + 687 = 31602
Step 47: 31602 + 687 = 32289
Step 48: 32289 + 687 = 32976
Step 49: 32976 + 687 = 33663
Step 50: 33663 + 687 = 34350
Step 51: 34350 + 687 = 35037
Step 52: 35037 + 687 = 35724
Step 53: 35724 + 687 = 36411
Step 54: 36411 + 687 = 37098
Step 55: 37098 + 687 = 37785
Step 56: 37785 + 687 = 38472
Step 57: 38472 + 687 = 39159
Step 58: 39159 + 687 = 39846
Step 59: 39846 + 687 = 40533
Step 60: 40533 + 687 = 41220
Step 61: 41220 + 687 = 41907
Step 62: 41907 + 687 = 42594
Step 63: 42594 + 687 = 43281
Step 64: 43281 + 687 = 43968
Step 65: 43968 + 687 = 44655
Step 66: 44655 + 687 = 45342
Step 67: 45342 + 687 = 46029
Step 68: 46029 + 687 = 46716
Step 69: 46716 + 687 = 47403
Step 70: 47403 + 687 = 48090
Step 71: 48090 + 687 = 48777
Step 72: 48777 + 687 = 49464
Step 73: 49464 + 687 = 50151
Step 74: 50151 + 687 = 50838
Step 75: 50838 + 687 = 51525
Step 76: 51525 + 687 = 52212
Step 77: 52212 + 687 = 52899
Step 78: 52899 + 687 = 53586
Step 79: 53586 + 687 = 54273
Step 80: 54273 + 687 = 54960
Step 81: 54960 + 687 = 55647
Step 82: 55647 + 687 = 56334
Step 83: 56334 + 687 = 57021
Step 84: 57021 + 687 = 57708
Step 85: 57708 + 687 = 58395
Step 86: 58395 + 687 = 59082
Step 87: 59082 + 687 = 59769
Step 88: 59769 + 687 = 60456
Step 89: 60456 + 687 = 61143
Step 90: 61143 + 687 = 61830
Step 91: 61830 + 687 = 62517
Step 92: 62517 + 687 = 63204
Step 93: 63204 + 687 = 63891
Step 94: 63891 + 687 = 64578
Step 95: 64578 + 687 = 65265
Step 96: 65265 + 687 = 65952
Step 97: 65952 + 687 = 66639
Step 98: 66639 + 687 = 67326
Step 99: 67326 + 687 = 68013
Step 100: 68013 + 687 = 68700
Step 101: 68700 + 687 = 69387
Step 102: 69387 + 687 = 70074
Step 103: 70074 + 687 = 70761
Step 104: 70761 + 687 = 71448
Step 105: 71448 + 687 = 72135
Step 106: 72135 + 687 = 72822
Step 107: 72822 + 687 = 73509
Step 108: 73509 + 687 = 74196
Step 109: 74196 + 687 = 74883
Step 110: 74883 + 687 = 75570
Step 111: 75570 + 687 = 76257
Step 112: 76257 + 687 = 76944
Step 113: 76944 + 687 = 77631
Step 114: 77631 + 687 = 78318
Step 115: 78318 + 687 = 79005
Step 116: 79005 + 687 = 79692
Step 117: 79692 + 687 = 80379
Step 118: 80379 + 687 = 81066
Step 119: 81066 + 687 = 81753
Step 120: 81753 + 687 = 82440
Step 121: 82440 + 687 = 83127
Step 122: 83127 + 687 = 83814
Step 123: 83814 + 687 = 84501
Step 124: 84501 + 687 = 85188
Step 125: 85188 + 687 = 85875
Step 126: 85875 + 687 = 86562
Step 127: 86562 + 687 = 87249
Step 128: 87249 + 687 = 87936
Step 129: 87936 + 687 = 88623
Step 130: 88623 + 687 = 89310
Step 131: 89310 + 687 = 89997
Step 132: 89997 + 687 = 90684
Step 133: 90684 + 687 = 91371
Step 134: 91371 + 687 = 92058
Step 135: 92058 + 687 = 92745
Step 136: 92745 + 687 = 93432
Step 137: 93432 + 687 = 94119
Step 138: 94119 + 687 = 94806
Step 139: 94806 + 687 = 95493
Step 140: 95493 + 687 = 96180
Step 141: 96180 + 687 = 96867
Step 142: 96867 + 687 = 97554
Step 143: 97554 + 687 = 98241
Step 144: 98241 + 687 = 98928
Step 145: 98928 + 687 = 99615
Step 146: 99615 + 687 = 100302
Step 147: 100302 + 687 = 100989
Step 148: 100989 + 687 = 101676
Step 149: 101676 + 687 = 102363
Step 150: 102363 + 687 = 103050
Step 151: 103050 + 687 = 103737
Step 152: 103737 + 687 = 104424
Step 153: 104424 + 687 = 105111
Step 154: 105111 + 687 = 105798
Step 155: 105798 + 687 = 106485
Step 156: 106485 + 687 = 107172
Step 157: 107172 + 687 = 107859
Step 158: 107859 + 687 = 108546
Step 159: 108546 + 687 = 109233
Step 160: 109233 + 687 = 109920
Step 161: 109920 + 687 = 110607
Step 162: 110607 + 687 = 111294
Step 163: 111294 + 687 = 111981
Step 164: 111981 + 687 = 112668
Step 165: 112668 + 687 = 113355
Step 166: 113355 + 687 = 114042
Step 167: 114042 + 687 = 114729
Step 168: 114729 + 687 = 115416
Step 169: 115416 + 687 = 116103
Step 170: 116103 + 687 = 116790
Step 171: 116790 + 687 = 117477
Step 172: 117477 + 687 = 118164
Step 173: 118164 + 687 = 118851
Step 174: 118851 + 687 = 119538
Step 175: 119538 + 687 = 120225
Step 176: 120225 + 687 = 120912
Step 177: 120912 + 687 = 121599
Step 178: 121599 + 687 = 122286
Step 179: 122286 + 687 = 122973
Step 180: 122973 + 687 = 123660
Step 181: 123660 + 687 = 124347
Step 182: 124347 + 687 = 125034
Step 183: 125034 + 687 = 125721
Step 184: 125721 + 687 = 126408
Step 185: 126408 + 687 = 127095
Step 186: 127095 + 687 = 127782
Step 187: 127782 + 687 = 128469

So, 687*187 = 128469