Marcie bought a 50 foot roll of packing tape she used two 8 5/6 foot lengths how much tape is left on the roll

So you know that we can do 50 - 8 which equals 42. 
42 is not the answer because there was a little more than 8 feet  used

So if you have 50 pizzas which are cut into 6 slices each and you at 8 of them you have 42 pizzas left. But if you eat 5 slices you have 41 and 1 slice left which is equal to 41 1/6

Hope this helps!!!