OK, let's work through this together. We're starting with 303 and we're going to multiply it by 14, which means we add 303 to itself 14 times.
Step 1: 0 + 303 = 303
Step 2: 303 + 303 = 606
Step 3: 606 + 303 = 909
Step 4: 909 + 303 = 1212
Step 5: 1212 + 303 = 1515
Step 6: 1515 + 303 = 1818
Step 7: 1818 + 303 = 2121
Step 8: 2121 + 303 = 2424
Step 9: 2424 + 303 = 2727
Step 10: 2727 + 303 = 3030
Step 11: 3030 + 303 = 3333
Step 12: 3333 + 303 = 3636
Step 13: 3636 + 303 = 3939
Step 14: 3939 + 303 = 4242

So, 303*14 = 4242