Alright, let's solve this math problem step by step. First, we have the number 109. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 90. So, we're going to take the number 109 and add it to itself 90 times.
Step 1: 0 + 109 = 109
Step 2: 109 + 109 = 218
Step 3: 218 + 109 = 327
Step 4: 327 + 109 = 436
Step 5: 436 + 109 = 545
Step 6: 545 + 109 = 654
Step 7: 654 + 109 = 763
Step 8: 763 + 109 = 872
Step 9: 872 + 109 = 981
Step 10: 981 + 109 = 1090
Step 11: 1090 + 109 = 1199
Step 12: 1199 + 109 = 1308
Step 13: 1308 + 109 = 1417
Step 14: 1417 + 109 = 1526
Step 15: 1526 + 109 = 1635
Step 16: 1635 + 109 = 1744
Step 17: 1744 + 109 = 1853
Step 18: 1853 + 109 = 1962
Step 19: 1962 + 109 = 2071
Step 20: 2071 + 109 = 2180
Step 21: 2180 + 109 = 2289
Step 22: 2289 + 109 = 2398
Step 23: 2398 + 109 = 2507
Step 24: 2507 + 109 = 2616
Step 25: 2616 + 109 = 2725
Step 26: 2725 + 109 = 2834
Step 27: 2834 + 109 = 2943
Step 28: 2943 + 109 = 3052
Step 29: 3052 + 109 = 3161
Step 30: 3161 + 109 = 3270
Step 31: 3270 + 109 = 3379
Step 32: 3379 + 109 = 3488
Step 33: 3488 + 109 = 3597
Step 34: 3597 + 109 = 3706
Step 35: 3706 + 109 = 3815
Step 36: 3815 + 109 = 3924
Step 37: 3924 + 109 = 4033
Step 38: 4033 + 109 = 4142
Step 39: 4142 + 109 = 4251
Step 40: 4251 + 109 = 4360
Step 41: 4360 + 109 = 4469
Step 42: 4469 + 109 = 4578
Step 43: 4578 + 109 = 4687
Step 44: 4687 + 109 = 4796
Step 45: 4796 + 109 = 4905
Step 46: 4905 + 109 = 5014
Step 47: 5014 + 109 = 5123
Step 48: 5123 + 109 = 5232
Step 49: 5232 + 109 = 5341
Step 50: 5341 + 109 = 5450
Step 51: 5450 + 109 = 5559
Step 52: 5559 + 109 = 5668
Step 53: 5668 + 109 = 5777
Step 54: 5777 + 109 = 5886
Step 55: 5886 + 109 = 5995
Step 56: 5995 + 109 = 6104
Step 57: 6104 + 109 = 6213
Step 58: 6213 + 109 = 6322
Step 59: 6322 + 109 = 6431
Step 60: 6431 + 109 = 6540
Step 61: 6540 + 109 = 6649
Step 62: 6649 + 109 = 6758
Step 63: 6758 + 109 = 6867
Step 64: 6867 + 109 = 6976
Step 65: 6976 + 109 = 7085
Step 66: 7085 + 109 = 7194
Step 67: 7194 + 109 = 7303
Step 68: 7303 + 109 = 7412
Step 69: 7412 + 109 = 7521
Step 70: 7521 + 109 = 7630
Step 71: 7630 + 109 = 7739
Step 72: 7739 + 109 = 7848
Step 73: 7848 + 109 = 7957
Step 74: 7957 + 109 = 8066
Step 75: 8066 + 109 = 8175
Step 76: 8175 + 109 = 8284
Step 77: 8284 + 109 = 8393
Step 78: 8393 + 109 = 8502
Step 79: 8502 + 109 = 8611
Step 80: 8611 + 109 = 8720
Step 81: 8720 + 109 = 8829
Step 82: 8829 + 109 = 8938
Step 83: 8938 + 109 = 9047
Step 84: 9047 + 109 = 9156
Step 85: 9156 + 109 = 9265
Step 86: 9265 + 109 = 9374
Step 87: 9374 + 109 = 9483
Step 88: 9483 + 109 = 9592
Step 89: 9592 + 109 = 9701
Step 90: 9701 + 109 = 9810

So, 109*90 = 9810