Let's get this math done. We have 91 and we're going to multiply it by 6. This is the same as taking 91 and adding it to itself 6 times.
Step 1: 0 + 91 = 91
Step 2: 91 + 91 = 182
Step 3: 182 + 91 = 273
Step 4: 273 + 91 = 364
Step 5: 364 + 91 = 455
Step 6: 455 + 91 = 546

So, 91*6 = 546