Sure thing! We've got 897 and we're gonna multiply it by 20. That's the same as adding 897 to itself 20 times.
Step 1: 0 + 897 = 897
Step 2: 897 + 897 = 1794
Step 3: 1794 + 897 = 2691
Step 4: 2691 + 897 = 3588
Step 5: 3588 + 897 = 4485
Step 6: 4485 + 897 = 5382
Step 7: 5382 + 897 = 6279
Step 8: 6279 + 897 = 7176
Step 9: 7176 + 897 = 8073
Step 10: 8073 + 897 = 8970
Step 11: 8970 + 897 = 9867
Step 12: 9867 + 897 = 10764
Step 13: 10764 + 897 = 11661
Step 14: 11661 + 897 = 12558
Step 15: 12558 + 897 = 13455
Step 16: 13455 + 897 = 14352
Step 17: 14352 + 897 = 15249
Step 18: 15249 + 897 = 16146
Step 19: 16146 + 897 = 17043
Step 20: 17043 + 897 = 17940

So, 897*20 = 17940