OK, let's work through this together. We're starting with 576 and we're going to multiply it by 27, which means we add 576 to itself 27 times.
Step 1: 0 + 576 = 576
Step 2: 576 + 576 = 1152
Step 3: 1152 + 576 = 1728
Step 4: 1728 + 576 = 2304
Step 5: 2304 + 576 = 2880
Step 6: 2880 + 576 = 3456
Step 7: 3456 + 576 = 4032
Step 8: 4032 + 576 = 4608
Step 9: 4608 + 576 = 5184
Step 10: 5184 + 576 = 5760
Step 11: 5760 + 576 = 6336
Step 12: 6336 + 576 = 6912
Step 13: 6912 + 576 = 7488
Step 14: 7488 + 576 = 8064
Step 15: 8064 + 576 = 8640
Step 16: 8640 + 576 = 9216
Step 17: 9216 + 576 = 9792
Step 18: 9792 + 576 = 10368
Step 19: 10368 + 576 = 10944
Step 20: 10944 + 576 = 11520
Step 21: 11520 + 576 = 12096
Step 22: 12096 + 576 = 12672
Step 23: 12672 + 576 = 13248
Step 24: 13248 + 576 = 13824
Step 25: 13824 + 576 = 14400
Step 26: 14400 + 576 = 14976
Step 27: 14976 + 576 = 15552

So, 576*27 = 15552