Sure thing, let's get straight to it. We start with 578 and we're going to multiply it by 15, which means adding 578 to itself 15 times.
Step 1: 0 + 578 = 578
Step 2: 578 + 578 = 1156
Step 3: 1156 + 578 = 1734
Step 4: 1734 + 578 = 2312
Step 5: 2312 + 578 = 2890
Step 6: 2890 + 578 = 3468
Step 7: 3468 + 578 = 4046
Step 8: 4046 + 578 = 4624
Step 9: 4624 + 578 = 5202
Step 10: 5202 + 578 = 5780
Step 11: 5780 + 578 = 6358
Step 12: 6358 + 578 = 6936
Step 13: 6936 + 578 = 7514
Step 14: 7514 + 578 = 8092
Step 15: 8092 + 578 = 8670

So, 578*15 = 8670