Alright, let's solve this math problem step by step. First, we have the number 429. 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 429 and add it to itself 90 times.
Step 1: 0 + 429 = 429
Step 2: 429 + 429 = 858
Step 3: 858 + 429 = 1287
Step 4: 1287 + 429 = 1716
Step 5: 1716 + 429 = 2145
Step 6: 2145 + 429 = 2574
Step 7: 2574 + 429 = 3003
Step 8: 3003 + 429 = 3432
Step 9: 3432 + 429 = 3861
Step 10: 3861 + 429 = 4290
Step 11: 4290 + 429 = 4719
Step 12: 4719 + 429 = 5148
Step 13: 5148 + 429 = 5577
Step 14: 5577 + 429 = 6006
Step 15: 6006 + 429 = 6435
Step 16: 6435 + 429 = 6864
Step 17: 6864 + 429 = 7293
Step 18: 7293 + 429 = 7722
Step 19: 7722 + 429 = 8151
Step 20: 8151 + 429 = 8580
Step 21: 8580 + 429 = 9009
Step 22: 9009 + 429 = 9438
Step 23: 9438 + 429 = 9867
Step 24: 9867 + 429 = 10296
Step 25: 10296 + 429 = 10725
Step 26: 10725 + 429 = 11154
Step 27: 11154 + 429 = 11583
Step 28: 11583 + 429 = 12012
Step 29: 12012 + 429 = 12441
Step 30: 12441 + 429 = 12870
Step 31: 12870 + 429 = 13299
Step 32: 13299 + 429 = 13728
Step 33: 13728 + 429 = 14157
Step 34: 14157 + 429 = 14586
Step 35: 14586 + 429 = 15015
Step 36: 15015 + 429 = 15444
Step 37: 15444 + 429 = 15873
Step 38: 15873 + 429 = 16302
Step 39: 16302 + 429 = 16731
Step 40: 16731 + 429 = 17160
Step 41: 17160 + 429 = 17589
Step 42: 17589 + 429 = 18018
Step 43: 18018 + 429 = 18447
Step 44: 18447 + 429 = 18876
Step 45: 18876 + 429 = 19305
Step 46: 19305 + 429 = 19734
Step 47: 19734 + 429 = 20163
Step 48: 20163 + 429 = 20592
Step 49: 20592 + 429 = 21021
Step 50: 21021 + 429 = 21450
Step 51: 21450 + 429 = 21879
Step 52: 21879 + 429 = 22308
Step 53: 22308 + 429 = 22737
Step 54: 22737 + 429 = 23166
Step 55: 23166 + 429 = 23595
Step 56: 23595 + 429 = 24024
Step 57: 24024 + 429 = 24453
Step 58: 24453 + 429 = 24882
Step 59: 24882 + 429 = 25311
Step 60: 25311 + 429 = 25740
Step 61: 25740 + 429 = 26169
Step 62: 26169 + 429 = 26598
Step 63: 26598 + 429 = 27027
Step 64: 27027 + 429 = 27456
Step 65: 27456 + 429 = 27885
Step 66: 27885 + 429 = 28314
Step 67: 28314 + 429 = 28743
Step 68: 28743 + 429 = 29172
Step 69: 29172 + 429 = 29601
Step 70: 29601 + 429 = 30030
Step 71: 30030 + 429 = 30459
Step 72: 30459 + 429 = 30888
Step 73: 30888 + 429 = 31317
Step 74: 31317 + 429 = 31746
Step 75: 31746 + 429 = 32175
Step 76: 32175 + 429 = 32604
Step 77: 32604 + 429 = 33033
Step 78: 33033 + 429 = 33462
Step 79: 33462 + 429 = 33891
Step 80: 33891 + 429 = 34320
Step 81: 34320 + 429 = 34749
Step 82: 34749 + 429 = 35178
Step 83: 35178 + 429 = 35607
Step 84: 35607 + 429 = 36036
Step 85: 36036 + 429 = 36465
Step 86: 36465 + 429 = 36894
Step 87: 36894 + 429 = 37323
Step 88: 37323 + 429 = 37752
Step 89: 37752 + 429 = 38181
Step 90: 38181 + 429 = 38610

So, 429*90 = 38610