# Why do we add meal to itself the second time when equating to total?

#1

after we have re asigned the variable meal to meal + meal * tax why would we add meal to meal again?

#2

this line:

``meal = meal + meal * tax``

?
Well, we want to update the meal variable. What should the new value be? The cost of the meal + the tax (tax is meal cost times tax)

#3

I was initially wondering the same thing. Basically the calculation you are doing is meal = meal + (meal * tax).

#4

Well the tax will be something like 3% or something around, I assume. So if the meal costs 40\$ and you multiply it with 0.03, you will have the tax for the meal only, but not how much you have to pay actually.

`meal (price of the meal at the cafeteria or whatever) = 40\$`

`tax = 40\$ * 0.03 = 1.2\$`

`meal (price you have to pay) = meal + tax = 41.2\$`

Makes sense, right?

#5

I'm confused as to why the total came out at 54.63, by the looks of line 7 `meal = meal + meal * tax` shouldn't that be two meals?

#6

No, because of order of operation. Multiply is before add/sum. Let's break it down:

``meal =``

we are going to assign a new value to our variable meal.
then because of order of operations, multiply is first:

``meal * tax``

which will give you the tax, which we then add to the meal costs:

``meal + (meal * tax)``

i put it in brackets, because we already calculated it. So now, we updated our variable and included the taxes