OK, let's work through this together. We're starting with 57 and we're going to multiply it by 8, which means we add 57 to itself 8 times.
Step 1: 0 + 57 = 57
Step 2: 57 + 57 = 114
Step 3: 114 + 57 = 171
Step 4: 171 + 57 = 228
Step 5: 228 + 57 = 285
Step 6: 285 + 57 = 342
Step 7: 342 + 57 = 399
Step 8: 399 + 57 = 456

So, 57*8 = 456