Let's roll up our sleeves and solve this. We have 426 and we're going to multiply it by 50, essentially adding 426 to itself 50 times.
Step 1: 0 + 426 = 426
Step 2: 426 + 426 = 852
Step 3: 852 + 426 = 1278
Step 4: 1278 + 426 = 1704
Step 5: 1704 + 426 = 2130
Step 6: 2130 + 426 = 2556
Step 7: 2556 + 426 = 2982
Step 8: 2982 + 426 = 3408
Step 9: 3408 + 426 = 3834
Step 10: 3834 + 426 = 4260
Step 11: 4260 + 426 = 4686
Step 12: 4686 + 426 = 5112
Step 13: 5112 + 426 = 5538
Step 14: 5538 + 426 = 5964
Step 15: 5964 + 426 = 6390
Step 16: 6390 + 426 = 6816
Step 17: 6816 + 426 = 7242
Step 18: 7242 + 426 = 7668
Step 19: 7668 + 426 = 8094
Step 20: 8094 + 426 = 8520
Step 21: 8520 + 426 = 8946
Step 22: 8946 + 426 = 9372
Step 23: 9372 + 426 = 9798
Step 24: 9798 + 426 = 10224
Step 25: 10224 + 426 = 10650
Step 26: 10650 + 426 = 11076
Step 27: 11076 + 426 = 11502
Step 28: 11502 + 426 = 11928
Step 29: 11928 + 426 = 12354
Step 30: 12354 + 426 = 12780
Step 31: 12780 + 426 = 13206
Step 32: 13206 + 426 = 13632
Step 33: 13632 + 426 = 14058
Step 34: 14058 + 426 = 14484
Step 35: 14484 + 426 = 14910
Step 36: 14910 + 426 = 15336
Step 37: 15336 + 426 = 15762
Step 38: 15762 + 426 = 16188
Step 39: 16188 + 426 = 16614
Step 40: 16614 + 426 = 17040
Step 41: 17040 + 426 = 17466
Step 42: 17466 + 426 = 17892
Step 43: 17892 + 426 = 18318
Step 44: 18318 + 426 = 18744
Step 45: 18744 + 426 = 19170
Step 46: 19170 + 426 = 19596
Step 47: 19596 + 426 = 20022
Step 48: 20022 + 426 = 20448
Step 49: 20448 + 426 = 20874
Step 50: 20874 + 426 = 21300

So, 426*50 = 21300