Let's roll up our sleeves and solve this. We have 728 and we're going to multiply it by 105, essentially adding 728 to itself 105 times.
Step 1: 0 + 728 = 728
Step 2: 728 + 728 = 1456
Step 3: 1456 + 728 = 2184
Step 4: 2184 + 728 = 2912
Step 5: 2912 + 728 = 3640
Step 6: 3640 + 728 = 4368
Step 7: 4368 + 728 = 5096
Step 8: 5096 + 728 = 5824
Step 9: 5824 + 728 = 6552
Step 10: 6552 + 728 = 7280
Step 11: 7280 + 728 = 8008
Step 12: 8008 + 728 = 8736
Step 13: 8736 + 728 = 9464
Step 14: 9464 + 728 = 10192
Step 15: 10192 + 728 = 10920
Step 16: 10920 + 728 = 11648
Step 17: 11648 + 728 = 12376
Step 18: 12376 + 728 = 13104
Step 19: 13104 + 728 = 13832
Step 20: 13832 + 728 = 14560
Step 21: 14560 + 728 = 15288
Step 22: 15288 + 728 = 16016
Step 23: 16016 + 728 = 16744
Step 24: 16744 + 728 = 17472
Step 25: 17472 + 728 = 18200
Step 26: 18200 + 728 = 18928
Step 27: 18928 + 728 = 19656
Step 28: 19656 + 728 = 20384
Step 29: 20384 + 728 = 21112
Step 30: 21112 + 728 = 21840
Step 31: 21840 + 728 = 22568
Step 32: 22568 + 728 = 23296
Step 33: 23296 + 728 = 24024
Step 34: 24024 + 728 = 24752
Step 35: 24752 + 728 = 25480
Step 36: 25480 + 728 = 26208
Step 37: 26208 + 728 = 26936
Step 38: 26936 + 728 = 27664
Step 39: 27664 + 728 = 28392
Step 40: 28392 + 728 = 29120
Step 41: 29120 + 728 = 29848
Step 42: 29848 + 728 = 30576
Step 43: 30576 + 728 = 31304
Step 44: 31304 + 728 = 32032
Step 45: 32032 + 728 = 32760
Step 46: 32760 + 728 = 33488
Step 47: 33488 + 728 = 34216
Step 48: 34216 + 728 = 34944
Step 49: 34944 + 728 = 35672
Step 50: 35672 + 728 = 36400
Step 51: 36400 + 728 = 37128
Step 52: 37128 + 728 = 37856
Step 53: 37856 + 728 = 38584
Step 54: 38584 + 728 = 39312
Step 55: 39312 + 728 = 40040
Step 56: 40040 + 728 = 40768
Step 57: 40768 + 728 = 41496
Step 58: 41496 + 728 = 42224
Step 59: 42224 + 728 = 42952
Step 60: 42952 + 728 = 43680
Step 61: 43680 + 728 = 44408
Step 62: 44408 + 728 = 45136
Step 63: 45136 + 728 = 45864
Step 64: 45864 + 728 = 46592
Step 65: 46592 + 728 = 47320
Step 66: 47320 + 728 = 48048
Step 67: 48048 + 728 = 48776
Step 68: 48776 + 728 = 49504
Step 69: 49504 + 728 = 50232
Step 70: 50232 + 728 = 50960
Step 71: 50960 + 728 = 51688
Step 72: 51688 + 728 = 52416
Step 73: 52416 + 728 = 53144
Step 74: 53144 + 728 = 53872
Step 75: 53872 + 728 = 54600
Step 76: 54600 + 728 = 55328
Step 77: 55328 + 728 = 56056
Step 78: 56056 + 728 = 56784
Step 79: 56784 + 728 = 57512
Step 80: 57512 + 728 = 58240
Step 81: 58240 + 728 = 58968
Step 82: 58968 + 728 = 59696
Step 83: 59696 + 728 = 60424
Step 84: 60424 + 728 = 61152
Step 85: 61152 + 728 = 61880
Step 86: 61880 + 728 = 62608
Step 87: 62608 + 728 = 63336
Step 88: 63336 + 728 = 64064
Step 89: 64064 + 728 = 64792
Step 90: 64792 + 728 = 65520
Step 91: 65520 + 728 = 66248
Step 92: 66248 + 728 = 66976
Step 93: 66976 + 728 = 67704
Step 94: 67704 + 728 = 68432
Step 95: 68432 + 728 = 69160
Step 96: 69160 + 728 = 69888
Step 97: 69888 + 728 = 70616
Step 98: 70616 + 728 = 71344
Step 99: 71344 + 728 = 72072
Step 100: 72072 + 728 = 72800
Step 101: 72800 + 728 = 73528
Step 102: 73528 + 728 = 74256
Step 103: 74256 + 728 = 74984
Step 104: 74984 + 728 = 75712
Step 105: 75712 + 728 = 76440

So, 728*105 = 76440