Without delay, let's solve this. We've got 672 and we will be multiplying it by 255, that is, adding 672 to itself 255 times.
Step 1: 0 + 672 = 672
Step 2: 672 + 672 = 1344
Step 3: 1344 + 672 = 2016
Step 4: 2016 + 672 = 2688
Step 5: 2688 + 672 = 3360
Step 6: 3360 + 672 = 4032
Step 7: 4032 + 672 = 4704
Step 8: 4704 + 672 = 5376
Step 9: 5376 + 672 = 6048
Step 10: 6048 + 672 = 6720
Step 11: 6720 + 672 = 7392
Step 12: 7392 + 672 = 8064
Step 13: 8064 + 672 = 8736
Step 14: 8736 + 672 = 9408
Step 15: 9408 + 672 = 10080
Step 16: 10080 + 672 = 10752
Step 17: 10752 + 672 = 11424
Step 18: 11424 + 672 = 12096
Step 19: 12096 + 672 = 12768
Step 20: 12768 + 672 = 13440
Step 21: 13440 + 672 = 14112
Step 22: 14112 + 672 = 14784
Step 23: 14784 + 672 = 15456
Step 24: 15456 + 672 = 16128
Step 25: 16128 + 672 = 16800
Step 26: 16800 + 672 = 17472
Step 27: 17472 + 672 = 18144
Step 28: 18144 + 672 = 18816
Step 29: 18816 + 672 = 19488
Step 30: 19488 + 672 = 20160
Step 31: 20160 + 672 = 20832
Step 32: 20832 + 672 = 21504
Step 33: 21504 + 672 = 22176
Step 34: 22176 + 672 = 22848
Step 35: 22848 + 672 = 23520
Step 36: 23520 + 672 = 24192
Step 37: 24192 + 672 = 24864
Step 38: 24864 + 672 = 25536
Step 39: 25536 + 672 = 26208
Step 40: 26208 + 672 = 26880
Step 41: 26880 + 672 = 27552
Step 42: 27552 + 672 = 28224
Step 43: 28224 + 672 = 28896
Step 44: 28896 + 672 = 29568
Step 45: 29568 + 672 = 30240
Step 46: 30240 + 672 = 30912
Step 47: 30912 + 672 = 31584
Step 48: 31584 + 672 = 32256
Step 49: 32256 + 672 = 32928
Step 50: 32928 + 672 = 33600
Step 51: 33600 + 672 = 34272
Step 52: 34272 + 672 = 34944
Step 53: 34944 + 672 = 35616
Step 54: 35616 + 672 = 36288
Step 55: 36288 + 672 = 36960
Step 56: 36960 + 672 = 37632
Step 57: 37632 + 672 = 38304
Step 58: 38304 + 672 = 38976
Step 59: 38976 + 672 = 39648
Step 60: 39648 + 672 = 40320
Step 61: 40320 + 672 = 40992
Step 62: 40992 + 672 = 41664
Step 63: 41664 + 672 = 42336
Step 64: 42336 + 672 = 43008
Step 65: 43008 + 672 = 43680
Step 66: 43680 + 672 = 44352
Step 67: 44352 + 672 = 45024
Step 68: 45024 + 672 = 45696
Step 69: 45696 + 672 = 46368
Step 70: 46368 + 672 = 47040
Step 71: 47040 + 672 = 47712
Step 72: 47712 + 672 = 48384
Step 73: 48384 + 672 = 49056
Step 74: 49056 + 672 = 49728
Step 75: 49728 + 672 = 50400
Step 76: 50400 + 672 = 51072
Step 77: 51072 + 672 = 51744
Step 78: 51744 + 672 = 52416
Step 79: 52416 + 672 = 53088
Step 80: 53088 + 672 = 53760
Step 81: 53760 + 672 = 54432
Step 82: 54432 + 672 = 55104
Step 83: 55104 + 672 = 55776
Step 84: 55776 + 672 = 56448
Step 85: 56448 + 672 = 57120
Step 86: 57120 + 672 = 57792
Step 87: 57792 + 672 = 58464
Step 88: 58464 + 672 = 59136
Step 89: 59136 + 672 = 59808
Step 90: 59808 + 672 = 60480
Step 91: 60480 + 672 = 61152
Step 92: 61152 + 672 = 61824
Step 93: 61824 + 672 = 62496
Step 94: 62496 + 672 = 63168
Step 95: 63168 + 672 = 63840
Step 96: 63840 + 672 = 64512
Step 97: 64512 + 672 = 65184
Step 98: 65184 + 672 = 65856
Step 99: 65856 + 672 = 66528
Step 100: 66528 + 672 = 67200
Step 101: 67200 + 672 = 67872
Step 102: 67872 + 672 = 68544
Step 103: 68544 + 672 = 69216
Step 104: 69216 + 672 = 69888
Step 105: 69888 + 672 = 70560
Step 106: 70560 + 672 = 71232
Step 107: 71232 + 672 = 71904
Step 108: 71904 + 672 = 72576
Step 109: 72576 + 672 = 73248
Step 110: 73248 + 672 = 73920
Step 111: 73920 + 672 = 74592
Step 112: 74592 + 672 = 75264
Step 113: 75264 + 672 = 75936
Step 114: 75936 + 672 = 76608
Step 115: 76608 + 672 = 77280
Step 116: 77280 + 672 = 77952
Step 117: 77952 + 672 = 78624
Step 118: 78624 + 672 = 79296
Step 119: 79296 + 672 = 79968
Step 120: 79968 + 672 = 80640
Step 121: 80640 + 672 = 81312
Step 122: 81312 + 672 = 81984
Step 123: 81984 + 672 = 82656
Step 124: 82656 + 672 = 83328
Step 125: 83328 + 672 = 84000
Step 126: 84000 + 672 = 84672
Step 127: 84672 + 672 = 85344
Step 128: 85344 + 672 = 86016
Step 129: 86016 + 672 = 86688
Step 130: 86688 + 672 = 87360
Step 131: 87360 + 672 = 88032
Step 132: 88032 + 672 = 88704
Step 133: 88704 + 672 = 89376
Step 134: 89376 + 672 = 90048
Step 135: 90048 + 672 = 90720
Step 136: 90720 + 672 = 91392
Step 137: 91392 + 672 = 92064
Step 138: 92064 + 672 = 92736
Step 139: 92736 + 672 = 93408
Step 140: 93408 + 672 = 94080
Step 141: 94080 + 672 = 94752
Step 142: 94752 + 672 = 95424
Step 143: 95424 + 672 = 96096
Step 144: 96096 + 672 = 96768
Step 145: 96768 + 672 = 97440
Step 146: 97440 + 672 = 98112
Step 147: 98112 + 672 = 98784
Step 148: 98784 + 672 = 99456
Step 149: 99456 + 672 = 100128
Step 150: 100128 + 672 = 100800
Step 151: 100800 + 672 = 101472
Step 152: 101472 + 672 = 102144
Step 153: 102144 + 672 = 102816
Step 154: 102816 + 672 = 103488
Step 155: 103488 + 672 = 104160
Step 156: 104160 + 672 = 104832
Step 157: 104832 + 672 = 105504
Step 158: 105504 + 672 = 106176
Step 159: 106176 + 672 = 106848
Step 160: 106848 + 672 = 107520
Step 161: 107520 + 672 = 108192
Step 162: 108192 + 672 = 108864
Step 163: 108864 + 672 = 109536
Step 164: 109536 + 672 = 110208
Step 165: 110208 + 672 = 110880
Step 166: 110880 + 672 = 111552
Step 167: 111552 + 672 = 112224
Step 168: 112224 + 672 = 112896
Step 169: 112896 + 672 = 113568
Step 170: 113568 + 672 = 114240
Step 171: 114240 + 672 = 114912
Step 172: 114912 + 672 = 115584
Step 173: 115584 + 672 = 116256
Step 174: 116256 + 672 = 116928
Step 175: 116928 + 672 = 117600
Step 176: 117600 + 672 = 118272
Step 177: 118272 + 672 = 118944
Step 178: 118944 + 672 = 119616
Step 179: 119616 + 672 = 120288
Step 180: 120288 + 672 = 120960
Step 181: 120960 + 672 = 121632
Step 182: 121632 + 672 = 122304
Step 183: 122304 + 672 = 122976
Step 184: 122976 + 672 = 123648
Step 185: 123648 + 672 = 124320
Step 186: 124320 + 672 = 124992
Step 187: 124992 + 672 = 125664
Step 188: 125664 + 672 = 126336
Step 189: 126336 + 672 = 127008
Step 190: 127008 + 672 = 127680
Step 191: 127680 + 672 = 128352
Step 192: 128352 + 672 = 129024
Step 193: 129024 + 672 = 129696
Step 194: 129696 + 672 = 130368
Step 195: 130368 + 672 = 131040
Step 196: 131040 + 672 = 131712
Step 197: 131712 + 672 = 132384
Step 198: 132384 + 672 = 133056
Step 199: 133056 + 672 = 133728
Step 200: 133728 + 672 = 134400
Step 201: 134400 + 672 = 135072
Step 202: 135072 + 672 = 135744
Step 203: 135744 + 672 = 136416
Step 204: 136416 + 672 = 137088
Step 205: 137088 + 672 = 137760
Step 206: 137760 + 672 = 138432
Step 207: 138432 + 672 = 139104
Step 208: 139104 + 672 = 139776
Step 209: 139776 + 672 = 140448
Step 210: 140448 + 672 = 141120
Step 211: 141120 + 672 = 141792
Step 212: 141792 + 672 = 142464
Step 213: 142464 + 672 = 143136
Step 214: 143136 + 672 = 143808
Step 215: 143808 + 672 = 144480
Step 216: 144480 + 672 = 145152
Step 217: 145152 + 672 = 145824
Step 218: 145824 + 672 = 146496
Step 219: 146496 + 672 = 147168
Step 220: 147168 + 672 = 147840
Step 221: 147840 + 672 = 148512
Step 222: 148512 + 672 = 149184
Step 223: 149184 + 672 = 149856
Step 224: 149856 + 672 = 150528
Step 225: 150528 + 672 = 151200
Step 226: 151200 + 672 = 151872
Step 227: 151872 + 672 = 152544
Step 228: 152544 + 672 = 153216
Step 229: 153216 + 672 = 153888
Step 230: 153888 + 672 = 154560
Step 231: 154560 + 672 = 155232
Step 232: 155232 + 672 = 155904
Step 233: 155904 + 672 = 156576
Step 234: 156576 + 672 = 157248
Step 235: 157248 + 672 = 157920
Step 236: 157920 + 672 = 158592
Step 237: 158592 + 672 = 159264
Step 238: 159264 + 672 = 159936
Step 239: 159936 + 672 = 160608
Step 240: 160608 + 672 = 161280
Step 241: 161280 + 672 = 161952
Step 242: 161952 + 672 = 162624
Step 243: 162624 + 672 = 163296
Step 244: 163296 + 672 = 163968
Step 245: 163968 + 672 = 164640
Step 246: 164640 + 672 = 165312
Step 247: 165312 + 672 = 165984
Step 248: 165984 + 672 = 166656
Step 249: 166656 + 672 = 167328
Step 250: 167328 + 672 = 168000
Step 251: 168000 + 672 = 168672
Step 252: 168672 + 672 = 169344
Step 253: 169344 + 672 = 170016
Step 254: 170016 + 672 = 170688
Step 255: 170688 + 672 = 171360

So, 672*255 = 171360