OK, let's crack this. We're given 557 and our task is to multiply it by 25. Essentially, we'll be adding 557 to itself 25 times.
Step 1: 0 + 557 = 557
Step 2: 557 + 557 = 1114
Step 3: 1114 + 557 = 1671
Step 4: 1671 + 557 = 2228
Step 5: 2228 + 557 = 2785
Step 6: 2785 + 557 = 3342
Step 7: 3342 + 557 = 3899
Step 8: 3899 + 557 = 4456
Step 9: 4456 + 557 = 5013
Step 10: 5013 + 557 = 5570
Step 11: 5570 + 557 = 6127
Step 12: 6127 + 557 = 6684
Step 13: 6684 + 557 = 7241
Step 14: 7241 + 557 = 7798
Step 15: 7798 + 557 = 8355
Step 16: 8355 + 557 = 8912
Step 17: 8912 + 557 = 9469
Step 18: 9469 + 557 = 10026
Step 19: 10026 + 557 = 10583
Step 20: 10583 + 557 = 11140
Step 21: 11140 + 557 = 11697
Step 22: 11697 + 557 = 12254
Step 23: 12254 + 557 = 12811
Step 24: 12811 + 557 = 13368
Step 25: 13368 + 557 = 13925

So, 557*25 = 13925