Sure thing! We've got 854 and we're gonna multiply it by 25. That's the same as adding 854 to itself 25 times.
Step 1: 0 + 854 = 854
Step 2: 854 + 854 = 1708
Step 3: 1708 + 854 = 2562
Step 4: 2562 + 854 = 3416
Step 5: 3416 + 854 = 4270
Step 6: 4270 + 854 = 5124
Step 7: 5124 + 854 = 5978
Step 8: 5978 + 854 = 6832
Step 9: 6832 + 854 = 7686
Step 10: 7686 + 854 = 8540
Step 11: 8540 + 854 = 9394
Step 12: 9394 + 854 = 10248
Step 13: 10248 + 854 = 11102
Step 14: 11102 + 854 = 11956
Step 15: 11956 + 854 = 12810
Step 16: 12810 + 854 = 13664
Step 17: 13664 + 854 = 14518
Step 18: 14518 + 854 = 15372
Step 19: 15372 + 854 = 16226
Step 20: 16226 + 854 = 17080
Step 21: 17080 + 854 = 17934
Step 22: 17934 + 854 = 18788
Step 23: 18788 + 854 = 19642
Step 24: 19642 + 854 = 20496
Step 25: 20496 + 854 = 21350

So, 854*25 = 21350