Without delay, let's solve this. We've got 413 and we will be multiplying it by 20, that is, adding 413 to itself 20 times.
Step 1: 0 + 413 = 413
Step 2: 413 + 413 = 826
Step 3: 826 + 413 = 1239
Step 4: 1239 + 413 = 1652
Step 5: 1652 + 413 = 2065
Step 6: 2065 + 413 = 2478
Step 7: 2478 + 413 = 2891
Step 8: 2891 + 413 = 3304
Step 9: 3304 + 413 = 3717
Step 10: 3717 + 413 = 4130
Step 11: 4130 + 413 = 4543
Step 12: 4543 + 413 = 4956
Step 13: 4956 + 413 = 5369
Step 14: 5369 + 413 = 5782
Step 15: 5782 + 413 = 6195
Step 16: 6195 + 413 = 6608
Step 17: 6608 + 413 = 7021
Step 18: 7021 + 413 = 7434
Step 19: 7434 + 413 = 7847
Step 20: 7847 + 413 = 8260

So, 413*20 = 8260