Let's roll up our sleeves and solve this. We have 98 and we're going to multiply it by 81, essentially adding 98 to itself 81 times.
Step 1: 0 + 98 = 98
Step 2: 98 + 98 = 196
Step 3: 196 + 98 = 294
Step 4: 294 + 98 = 392
Step 5: 392 + 98 = 490
Step 6: 490 + 98 = 588
Step 7: 588 + 98 = 686
Step 8: 686 + 98 = 784
Step 9: 784 + 98 = 882
Step 10: 882 + 98 = 980
Step 11: 980 + 98 = 1078
Step 12: 1078 + 98 = 1176
Step 13: 1176 + 98 = 1274
Step 14: 1274 + 98 = 1372
Step 15: 1372 + 98 = 1470
Step 16: 1470 + 98 = 1568
Step 17: 1568 + 98 = 1666
Step 18: 1666 + 98 = 1764
Step 19: 1764 + 98 = 1862
Step 20: 1862 + 98 = 1960
Step 21: 1960 + 98 = 2058
Step 22: 2058 + 98 = 2156
Step 23: 2156 + 98 = 2254
Step 24: 2254 + 98 = 2352
Step 25: 2352 + 98 = 2450
Step 26: 2450 + 98 = 2548
Step 27: 2548 + 98 = 2646
Step 28: 2646 + 98 = 2744
Step 29: 2744 + 98 = 2842
Step 30: 2842 + 98 = 2940
Step 31: 2940 + 98 = 3038
Step 32: 3038 + 98 = 3136
Step 33: 3136 + 98 = 3234
Step 34: 3234 + 98 = 3332
Step 35: 3332 + 98 = 3430
Step 36: 3430 + 98 = 3528
Step 37: 3528 + 98 = 3626
Step 38: 3626 + 98 = 3724
Step 39: 3724 + 98 = 3822
Step 40: 3822 + 98 = 3920
Step 41: 3920 + 98 = 4018
Step 42: 4018 + 98 = 4116
Step 43: 4116 + 98 = 4214
Step 44: 4214 + 98 = 4312
Step 45: 4312 + 98 = 4410
Step 46: 4410 + 98 = 4508
Step 47: 4508 + 98 = 4606
Step 48: 4606 + 98 = 4704
Step 49: 4704 + 98 = 4802
Step 50: 4802 + 98 = 4900
Step 51: 4900 + 98 = 4998
Step 52: 4998 + 98 = 5096
Step 53: 5096 + 98 = 5194
Step 54: 5194 + 98 = 5292
Step 55: 5292 + 98 = 5390
Step 56: 5390 + 98 = 5488
Step 57: 5488 + 98 = 5586
Step 58: 5586 + 98 = 5684
Step 59: 5684 + 98 = 5782
Step 60: 5782 + 98 = 5880
Step 61: 5880 + 98 = 5978
Step 62: 5978 + 98 = 6076
Step 63: 6076 + 98 = 6174
Step 64: 6174 + 98 = 6272
Step 65: 6272 + 98 = 6370
Step 66: 6370 + 98 = 6468
Step 67: 6468 + 98 = 6566
Step 68: 6566 + 98 = 6664
Step 69: 6664 + 98 = 6762
Step 70: 6762 + 98 = 6860
Step 71: 6860 + 98 = 6958
Step 72: 6958 + 98 = 7056
Step 73: 7056 + 98 = 7154
Step 74: 7154 + 98 = 7252
Step 75: 7252 + 98 = 7350
Step 76: 7350 + 98 = 7448
Step 77: 7448 + 98 = 7546
Step 78: 7546 + 98 = 7644
Step 79: 7644 + 98 = 7742
Step 80: 7742 + 98 = 7840
Step 81: 7840 + 98 = 7938

So, 98*81 = 7938