Without delay, let's solve this. We've got 866 and we will be multiplying it by 20, that is, adding 866 to itself 20 times.
Step 1: 0 + 866 = 866
Step 2: 866 + 866 = 1732
Step 3: 1732 + 866 = 2598
Step 4: 2598 + 866 = 3464
Step 5: 3464 + 866 = 4330
Step 6: 4330 + 866 = 5196
Step 7: 5196 + 866 = 6062
Step 8: 6062 + 866 = 6928
Step 9: 6928 + 866 = 7794
Step 10: 7794 + 866 = 8660
Step 11: 8660 + 866 = 9526
Step 12: 9526 + 866 = 10392
Step 13: 10392 + 866 = 11258
Step 14: 11258 + 866 = 12124
Step 15: 12124 + 866 = 12990
Step 16: 12990 + 866 = 13856
Step 17: 13856 + 866 = 14722
Step 18: 14722 + 866 = 15588
Step 19: 15588 + 866 = 16454
Step 20: 16454 + 866 = 17320

So, 866*20 = 17320