Without delay, let's solve this. We've got 601 and we will be multiplying it by 25, that is, adding 601 to itself 25 times.
Step 1: 0 + 601 = 601
Step 2: 601 + 601 = 1202
Step 3: 1202 + 601 = 1803
Step 4: 1803 + 601 = 2404
Step 5: 2404 + 601 = 3005
Step 6: 3005 + 601 = 3606
Step 7: 3606 + 601 = 4207
Step 8: 4207 + 601 = 4808
Step 9: 4808 + 601 = 5409
Step 10: 5409 + 601 = 6010
Step 11: 6010 + 601 = 6611
Step 12: 6611 + 601 = 7212
Step 13: 7212 + 601 = 7813
Step 14: 7813 + 601 = 8414
Step 15: 8414 + 601 = 9015
Step 16: 9015 + 601 = 9616
Step 17: 9616 + 601 = 10217
Step 18: 10217 + 601 = 10818
Step 19: 10818 + 601 = 11419
Step 20: 11419 + 601 = 12020
Step 21: 12020 + 601 = 12621
Step 22: 12621 + 601 = 13222
Step 23: 13222 + 601 = 13823
Step 24: 13823 + 601 = 14424
Step 25: 14424 + 601 = 15025

So, 601*25 = 15025