OK, let's crack this. We're given 904 and our task is to multiply it by 25. Essentially, we'll be adding 904 to itself 25 times.
Step 1: 0 + 904 = 904
Step 2: 904 + 904 = 1808
Step 3: 1808 + 904 = 2712
Step 4: 2712 + 904 = 3616
Step 5: 3616 + 904 = 4520
Step 6: 4520 + 904 = 5424
Step 7: 5424 + 904 = 6328
Step 8: 6328 + 904 = 7232
Step 9: 7232 + 904 = 8136
Step 10: 8136 + 904 = 9040
Step 11: 9040 + 904 = 9944
Step 12: 9944 + 904 = 10848
Step 13: 10848 + 904 = 11752
Step 14: 11752 + 904 = 12656
Step 15: 12656 + 904 = 13560
Step 16: 13560 + 904 = 14464
Step 17: 14464 + 904 = 15368
Step 18: 15368 + 904 = 16272
Step 19: 16272 + 904 = 17176
Step 20: 17176 + 904 = 18080
Step 21: 18080 + 904 = 18984
Step 22: 18984 + 904 = 19888
Step 23: 19888 + 904 = 20792
Step 24: 20792 + 904 = 21696
Step 25: 21696 + 904 = 22600

So, 904*25 = 22600