SOLUTION: At Enzo's Pizza Parlor, there are 7 different toppings, where a customer can order any number of these toppings. If you dine at the said pizza dinner, with how many possible can yo

There are 2 choices you can make for each topping, they are:

Choice 1: "Yes, I want that topping put on my pizza."
Choice 2: "No, I don't want that topping put on my pizza."

You can make a choice about the 1st topping in 2 ways.
For both those choices, you can make a choice about the 
2nd topping in 2 ways.

That's 2×2 ways to make choices about the first 2 toppings. 

For those 2×2 choices you can make for the first 2 toppings, 
you can make a choice about the 3rd topping in 2 ways.
That's 2×2×2 ways to make choices about the first 3 toppings. 

For those 2×2×2 choices you can make for the first 3 toppings, 
you can make a choice about the 4th topping in 2 ways.
That's 2×2×2×2 ways to make choices about the first 4 toppings.

For those 2×2×2×2 choices you can make for the first 4 toppings, 
you can make a choice about the 5th topping in 2 ways.
That's 2×2×2×2×2 ways to make choices about the first 5 toppings.

For those 2×2×2×2×2 choices you can make for the first 5 toppings, 
you can make a choice about the 6th topping in 2 ways.
That's 2×2×2×2×2×2 ways to make choices about the first 6 toppings.

For those 2×2×2×2×2×2 choices you can make for the first 6 toppings, 
you can make a choice about the 7th topping in 2 ways.
That's 2×2×2×2×2×2×2 ways to make choices about the 7 toppings. 

Answer 2×2×2×2×2×2×2 = 27 = 128 ways to make choices
about your pizza.

However, if you said "no" to all those toppings then all you have is
a pizza crust! :)  So maybe a pizza crust is not considered a pizza,
and so your teacher might say that the answer is only 127 instead of
128.  :)

Edwin