Math--Sad but true...

this is a copy of an email i was sent. The end is cut off a bit but you'll get the idea.

>Last week I purchased a burger for $1.58. The counter girl took my $2
>and I was digging for my change when I pulled 8 cents from my pocket
>and gave it to her. She stood there, holding the nickel and 3 pennies,
>while looking at the screen on her register.
>
>I sensed her discomfort and tried to tell her to just give me two
>quarters, but she hailed the manager for help.
>
>While he tried to explain the transaction to her, she stood there and
>cried.
>
>Why do I tell you this?
>
>Please read more about the "history of teaching math":
>
>Teaching Math In 1950
>
>************************ A logger sells a truckload of lumber for $100.
>His cost of production is 4/5 of the price. What is his profit?
>
>Teaching Math In 1960
>
>************************ A logger sells a truckload of lumber for $100.
>His cost of production is 4/5 of the price, or $80. What is his profit?
>
>Teaching Math In 1970
>
>************************ A logger sells a truckload of lumber for $100.
>His cost of production is $80. Did he make a profit?
>
>Teaching Math In 1980
>
>*********************** A logger sells a truckload of lumber for $100.
>His cost of production is $80 and his profit is $20. Your assignment:
>Underline the number 20.
>
>Teaching Math In 1990
>
>************************ By cutting down beautiful forest trees, the
>logger makes $20. What do you think of this way of making a living?
>Topic for class participation after answering the question: How did the

>forest birds and squirrels feel as the logger cut down the trees.
>(There are no wrong answers.)
>
>Teaching Math In 2005
>
>************************El hachero vende un camion carga por $100. La
>cuesta de production es