OK, let's work through this together. We're starting with 634 and we're going to multiply it by 26, which means we add 634 to itself 26 times.
Step 1: 0 + 634 = 634
Step 2: 634 + 634 = 1268
Step 3: 1268 + 634 = 1902
Step 4: 1902 + 634 = 2536
Step 5: 2536 + 634 = 3170
Step 6: 3170 + 634 = 3804
Step 7: 3804 + 634 = 4438
Step 8: 4438 + 634 = 5072
Step 9: 5072 + 634 = 5706
Step 10: 5706 + 634 = 6340
Step 11: 6340 + 634 = 6974
Step 12: 6974 + 634 = 7608
Step 13: 7608 + 634 = 8242
Step 14: 8242 + 634 = 8876
Step 15: 8876 + 634 = 9510
Step 16: 9510 + 634 = 10144
Step 17: 10144 + 634 = 10778
Step 18: 10778 + 634 = 11412
Step 19: 11412 + 634 = 12046
Step 20: 12046 + 634 = 12680
Step 21: 12680 + 634 = 13314
Step 22: 13314 + 634 = 13948
Step 23: 13948 + 634 = 14582
Step 24: 14582 + 634 = 15216
Step 25: 15216 + 634 = 15850
Step 26: 15850 + 634 = 16484

So, 634*26 = 16484