Alright, let's solve this math problem step by step. First, we have the number 663. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 73. So, we're going to take the number 663 and add it to itself 73 times.
Step 1: 0 + 663 = 663
Step 2: 663 + 663 = 1326
Step 3: 1326 + 663 = 1989
Step 4: 1989 + 663 = 2652
Step 5: 2652 + 663 = 3315
Step 6: 3315 + 663 = 3978
Step 7: 3978 + 663 = 4641
Step 8: 4641 + 663 = 5304
Step 9: 5304 + 663 = 5967
Step 10: 5967 + 663 = 6630
Step 11: 6630 + 663 = 7293
Step 12: 7293 + 663 = 7956
Step 13: 7956 + 663 = 8619
Step 14: 8619 + 663 = 9282
Step 15: 9282 + 663 = 9945
Step 16: 9945 + 663 = 10608
Step 17: 10608 + 663 = 11271
Step 18: 11271 + 663 = 11934
Step 19: 11934 + 663 = 12597
Step 20: 12597 + 663 = 13260
Step 21: 13260 + 663 = 13923
Step 22: 13923 + 663 = 14586
Step 23: 14586 + 663 = 15249
Step 24: 15249 + 663 = 15912
Step 25: 15912 + 663 = 16575
Step 26: 16575 + 663 = 17238
Step 27: 17238 + 663 = 17901
Step 28: 17901 + 663 = 18564
Step 29: 18564 + 663 = 19227
Step 30: 19227 + 663 = 19890
Step 31: 19890 + 663 = 20553
Step 32: 20553 + 663 = 21216
Step 33: 21216 + 663 = 21879
Step 34: 21879 + 663 = 22542
Step 35: 22542 + 663 = 23205
Step 36: 23205 + 663 = 23868
Step 37: 23868 + 663 = 24531
Step 38: 24531 + 663 = 25194
Step 39: 25194 + 663 = 25857
Step 40: 25857 + 663 = 26520
Step 41: 26520 + 663 = 27183
Step 42: 27183 + 663 = 27846
Step 43: 27846 + 663 = 28509
Step 44: 28509 + 663 = 29172
Step 45: 29172 + 663 = 29835
Step 46: 29835 + 663 = 30498
Step 47: 30498 + 663 = 31161
Step 48: 31161 + 663 = 31824
Step 49: 31824 + 663 = 32487
Step 50: 32487 + 663 = 33150
Step 51: 33150 + 663 = 33813
Step 52: 33813 + 663 = 34476
Step 53: 34476 + 663 = 35139
Step 54: 35139 + 663 = 35802
Step 55: 35802 + 663 = 36465
Step 56: 36465 + 663 = 37128
Step 57: 37128 + 663 = 37791
Step 58: 37791 + 663 = 38454
Step 59: 38454 + 663 = 39117
Step 60: 39117 + 663 = 39780
Step 61: 39780 + 663 = 40443
Step 62: 40443 + 663 = 41106
Step 63: 41106 + 663 = 41769
Step 64: 41769 + 663 = 42432
Step 65: 42432 + 663 = 43095
Step 66: 43095 + 663 = 43758
Step 67: 43758 + 663 = 44421
Step 68: 44421 + 663 = 45084
Step 69: 45084 + 663 = 45747
Step 70: 45747 + 663 = 46410
Step 71: 46410 + 663 = 47073
Step 72: 47073 + 663 = 47736
Step 73: 47736 + 663 = 48399

So, 663*73 = 48399