Let's roll up our sleeves and solve this. We have 573 and we're going to multiply it by 36, essentially adding 573 to itself 36 times.
Step 1: 0 + 573 = 573
Step 2: 573 + 573 = 1146
Step 3: 1146 + 573 = 1719
Step 4: 1719 + 573 = 2292
Step 5: 2292 + 573 = 2865
Step 6: 2865 + 573 = 3438
Step 7: 3438 + 573 = 4011
Step 8: 4011 + 573 = 4584
Step 9: 4584 + 573 = 5157
Step 10: 5157 + 573 = 5730
Step 11: 5730 + 573 = 6303
Step 12: 6303 + 573 = 6876
Step 13: 6876 + 573 = 7449
Step 14: 7449 + 573 = 8022
Step 15: 8022 + 573 = 8595
Step 16: 8595 + 573 = 9168
Step 17: 9168 + 573 = 9741
Step 18: 9741 + 573 = 10314
Step 19: 10314 + 573 = 10887
Step 20: 10887 + 573 = 11460
Step 21: 11460 + 573 = 12033
Step 22: 12033 + 573 = 12606
Step 23: 12606 + 573 = 13179
Step 24: 13179 + 573 = 13752
Step 25: 13752 + 573 = 14325
Step 26: 14325 + 573 = 14898
Step 27: 14898 + 573 = 15471
Step 28: 15471 + 573 = 16044
Step 29: 16044 + 573 = 16617
Step 30: 16617 + 573 = 17190
Step 31: 17190 + 573 = 17763
Step 32: 17763 + 573 = 18336
Step 33: 18336 + 573 = 18909
Step 34: 18909 + 573 = 19482
Step 35: 19482 + 573 = 20055
Step 36: 20055 + 573 = 20628

So, 573*36 = 20628