OK, let's crack this. We're given 303 and our task is to multiply it by 10. Essentially, we'll be adding 303 to itself 10 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

So, 303*10 = 3030