Alright, let's solve this math problem step by step. First, we have the number 398. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 100. So, we're going to take the number 398 and add it to itself 100 times.
Step 1: 0 + 398 = 398
Step 2: 398 + 398 = 796
Step 3: 796 + 398 = 1194
Step 4: 1194 + 398 = 1592
Step 5: 1592 + 398 = 1990
Step 6: 1990 + 398 = 2388
Step 7: 2388 + 398 = 2786
Step 8: 2786 + 398 = 3184
Step 9: 3184 + 398 = 3582
Step 10: 3582 + 398 = 3980
Step 11: 3980 + 398 = 4378
Step 12: 4378 + 398 = 4776
Step 13: 4776 + 398 = 5174
Step 14: 5174 + 398 = 5572
Step 15: 5572 + 398 = 5970
Step 16: 5970 + 398 = 6368
Step 17: 6368 + 398 = 6766
Step 18: 6766 + 398 = 7164
Step 19: 7164 + 398 = 7562
Step 20: 7562 + 398 = 7960
Step 21: 7960 + 398 = 8358
Step 22: 8358 + 398 = 8756
Step 23: 8756 + 398 = 9154
Step 24: 9154 + 398 = 9552
Step 25: 9552 + 398 = 9950
Step 26: 9950 + 398 = 10348
Step 27: 10348 + 398 = 10746
Step 28: 10746 + 398 = 11144
Step 29: 11144 + 398 = 11542
Step 30: 11542 + 398 = 11940
Step 31: 11940 + 398 = 12338
Step 32: 12338 + 398 = 12736
Step 33: 12736 + 398 = 13134
Step 34: 13134 + 398 = 13532
Step 35: 13532 + 398 = 13930
Step 36: 13930 + 398 = 14328
Step 37: 14328 + 398 = 14726
Step 38: 14726 + 398 = 15124
Step 39: 15124 + 398 = 15522
Step 40: 15522 + 398 = 15920
Step 41: 15920 + 398 = 16318
Step 42: 16318 + 398 = 16716
Step 43: 16716 + 398 = 17114
Step 44: 17114 + 398 = 17512
Step 45: 17512 + 398 = 17910
Step 46: 17910 + 398 = 18308
Step 47: 18308 + 398 = 18706
Step 48: 18706 + 398 = 19104
Step 49: 19104 + 398 = 19502
Step 50: 19502 + 398 = 19900
Step 51: 19900 + 398 = 20298
Step 52: 20298 + 398 = 20696
Step 53: 20696 + 398 = 21094
Step 54: 21094 + 398 = 21492
Step 55: 21492 + 398 = 21890
Step 56: 21890 + 398 = 22288
Step 57: 22288 + 398 = 22686
Step 58: 22686 + 398 = 23084
Step 59: 23084 + 398 = 23482
Step 60: 23482 + 398 = 23880
Step 61: 23880 + 398 = 24278
Step 62: 24278 + 398 = 24676
Step 63: 24676 + 398 = 25074
Step 64: 25074 + 398 = 25472
Step 65: 25472 + 398 = 25870
Step 66: 25870 + 398 = 26268
Step 67: 26268 + 398 = 26666
Step 68: 26666 + 398 = 27064
Step 69: 27064 + 398 = 27462
Step 70: 27462 + 398 = 27860
Step 71: 27860 + 398 = 28258
Step 72: 28258 + 398 = 28656
Step 73: 28656 + 398 = 29054
Step 74: 29054 + 398 = 29452
Step 75: 29452 + 398 = 29850
Step 76: 29850 + 398 = 30248
Step 77: 30248 + 398 = 30646
Step 78: 30646 + 398 = 31044
Step 79: 31044 + 398 = 31442
Step 80: 31442 + 398 = 31840
Step 81: 31840 + 398 = 32238
Step 82: 32238 + 398 = 32636
Step 83: 32636 + 398 = 33034
Step 84: 33034 + 398 = 33432
Step 85: 33432 + 398 = 33830
Step 86: 33830 + 398 = 34228
Step 87: 34228 + 398 = 34626
Step 88: 34626 + 398 = 35024
Step 89: 35024 + 398 = 35422
Step 90: 35422 + 398 = 35820
Step 91: 35820 + 398 = 36218
Step 92: 36218 + 398 = 36616
Step 93: 36616 + 398 = 37014
Step 94: 37014 + 398 = 37412
Step 95: 37412 + 398 = 37810
Step 96: 37810 + 398 = 38208
Step 97: 38208 + 398 = 38606
Step 98: 38606 + 398 = 39004
Step 99: 39004 + 398 = 39402
Step 100: 39402 + 398 = 39800

So, 398*100 = 39800