OK, let's crack this. We're given 915 and our task is to multiply it by 8. Essentially, we'll be adding 915 to itself 8 times.
Step 1: 0 + 915 = 915
Step 2: 915 + 915 = 1830
Step 3: 1830 + 915 = 2745
Step 4: 2745 + 915 = 3660
Step 5: 3660 + 915 = 4575
Step 6: 4575 + 915 = 5490
Step 7: 5490 + 915 = 6405
Step 8: 6405 + 915 = 7320

So, 915*8 = 7320