OK, let's crack this. We're given 504 and our task is to multiply it by 36. Essentially, we'll be adding 504 to itself 36 times.
Step 1: 0 + 504 = 504
Step 2: 504 + 504 = 1008
Step 3: 1008 + 504 = 1512
Step 4: 1512 + 504 = 2016
Step 5: 2016 + 504 = 2520
Step 6: 2520 + 504 = 3024
Step 7: 3024 + 504 = 3528
Step 8: 3528 + 504 = 4032
Step 9: 4032 + 504 = 4536
Step 10: 4536 + 504 = 5040
Step 11: 5040 + 504 = 5544
Step 12: 5544 + 504 = 6048
Step 13: 6048 + 504 = 6552
Step 14: 6552 + 504 = 7056
Step 15: 7056 + 504 = 7560
Step 16: 7560 + 504 = 8064
Step 17: 8064 + 504 = 8568
Step 18: 8568 + 504 = 9072
Step 19: 9072 + 504 = 9576
Step 20: 9576 + 504 = 10080
Step 21: 10080 + 504 = 10584
Step 22: 10584 + 504 = 11088
Step 23: 11088 + 504 = 11592
Step 24: 11592 + 504 = 12096
Step 25: 12096 + 504 = 12600
Step 26: 12600 + 504 = 13104
Step 27: 13104 + 504 = 13608
Step 28: 13608 + 504 = 14112
Step 29: 14112 + 504 = 14616
Step 30: 14616 + 504 = 15120
Step 31: 15120 + 504 = 15624
Step 32: 15624 + 504 = 16128
Step 33: 16128 + 504 = 16632
Step 34: 16632 + 504 = 17136
Step 35: 17136 + 504 = 17640
Step 36: 17640 + 504 = 18144

So, 504*36 = 18144