Sure thing, let's get straight to it. We start with 861 and we're going to multiply it by 51, which means adding 861 to itself 51 times.
Step 1: 0 + 861 = 861
Step 2: 861 + 861 = 1722
Step 3: 1722 + 861 = 2583
Step 4: 2583 + 861 = 3444
Step 5: 3444 + 861 = 4305
Step 6: 4305 + 861 = 5166
Step 7: 5166 + 861 = 6027
Step 8: 6027 + 861 = 6888
Step 9: 6888 + 861 = 7749
Step 10: 7749 + 861 = 8610
Step 11: 8610 + 861 = 9471
Step 12: 9471 + 861 = 10332
Step 13: 10332 + 861 = 11193
Step 14: 11193 + 861 = 12054
Step 15: 12054 + 861 = 12915
Step 16: 12915 + 861 = 13776
Step 17: 13776 + 861 = 14637
Step 18: 14637 + 861 = 15498
Step 19: 15498 + 861 = 16359
Step 20: 16359 + 861 = 17220
Step 21: 17220 + 861 = 18081
Step 22: 18081 + 861 = 18942
Step 23: 18942 + 861 = 19803
Step 24: 19803 + 861 = 20664
Step 25: 20664 + 861 = 21525
Step 26: 21525 + 861 = 22386
Step 27: 22386 + 861 = 23247
Step 28: 23247 + 861 = 24108
Step 29: 24108 + 861 = 24969
Step 30: 24969 + 861 = 25830
Step 31: 25830 + 861 = 26691
Step 32: 26691 + 861 = 27552
Step 33: 27552 + 861 = 28413
Step 34: 28413 + 861 = 29274
Step 35: 29274 + 861 = 30135
Step 36: 30135 + 861 = 30996
Step 37: 30996 + 861 = 31857
Step 38: 31857 + 861 = 32718
Step 39: 32718 + 861 = 33579
Step 40: 33579 + 861 = 34440
Step 41: 34440 + 861 = 35301
Step 42: 35301 + 861 = 36162
Step 43: 36162 + 861 = 37023
Step 44: 37023 + 861 = 37884
Step 45: 37884 + 861 = 38745
Step 46: 38745 + 861 = 39606
Step 47: 39606 + 861 = 40467
Step 48: 40467 + 861 = 41328
Step 49: 41328 + 861 = 42189
Step 50: 42189 + 861 = 43050
Step 51: 43050 + 861 = 43911

So, 861*51 = 43911