OK, let's work through this together. We're starting with 102 and we're going to multiply it by 18, which means we add 102 to itself 18 times.
Step 1: 0 + 102 = 102
Step 2: 102 + 102 = 204
Step 3: 204 + 102 = 306
Step 4: 306 + 102 = 408
Step 5: 408 + 102 = 510
Step 6: 510 + 102 = 612
Step 7: 612 + 102 = 714
Step 8: 714 + 102 = 816
Step 9: 816 + 102 = 918
Step 10: 918 + 102 = 1020
Step 11: 1020 + 102 = 1122
Step 12: 1122 + 102 = 1224
Step 13: 1224 + 102 = 1326
Step 14: 1326 + 102 = 1428
Step 15: 1428 + 102 = 1530
Step 16: 1530 + 102 = 1632
Step 17: 1632 + 102 = 1734
Step 18: 1734 + 102 = 1836

So, 102*18 = 1836