Sure thing, let's get straight to it. We start with 566 and we're going to multiply it by 21, which means adding 566 to itself 21 times.
Step 1: 0 + 566 = 566
Step 2: 566 + 566 = 1132
Step 3: 1132 + 566 = 1698
Step 4: 1698 + 566 = 2264
Step 5: 2264 + 566 = 2830
Step 6: 2830 + 566 = 3396
Step 7: 3396 + 566 = 3962
Step 8: 3962 + 566 = 4528
Step 9: 4528 + 566 = 5094
Step 10: 5094 + 566 = 5660
Step 11: 5660 + 566 = 6226
Step 12: 6226 + 566 = 6792
Step 13: 6792 + 566 = 7358
Step 14: 7358 + 566 = 7924
Step 15: 7924 + 566 = 8490
Step 16: 8490 + 566 = 9056
Step 17: 9056 + 566 = 9622
Step 18: 9622 + 566 = 10188
Step 19: 10188 + 566 = 10754
Step 20: 10754 + 566 = 11320
Step 21: 11320 + 566 = 11886

So, 566*21 = 11886