OK, let's crack this. We're given 203 and our task is to multiply it by 15. Essentially, we'll be adding 203 to itself 15 times.
Step 1: 0 + 203 = 203
Step 2: 203 + 203 = 406
Step 3: 406 + 203 = 609
Step 4: 609 + 203 = 812
Step 5: 812 + 203 = 1015
Step 6: 1015 + 203 = 1218
Step 7: 1218 + 203 = 1421
Step 8: 1421 + 203 = 1624
Step 9: 1624 + 203 = 1827
Step 10: 1827 + 203 = 2030
Step 11: 2030 + 203 = 2233
Step 12: 2233 + 203 = 2436
Step 13: 2436 + 203 = 2639
Step 14: 2639 + 203 = 2842
Step 15: 2842 + 203 = 3045

So, 203*15 = 3045