Teaching Math

[Hammer]

Received this in an e-mail from a Brit friend in ELH:

Subject: 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 exchanges a set "L" of lumber for a set "M"
of money. The cardinality of set "M" is 100. Each
element is worth one dollar. Make 100 dots
representing the elements of the set "M." The set "C",
the cost of production contains 20 fewer points than
set "M." Represent the set "C" as a subset of
set "M" and answer the following question: What is the
cardinality of the set "P" of profits?

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 2002:
A logger sells a truckload of lumber for $100. His
cost of production is $120. How does Arthur Andersen
determine that his profit margin is $60?

Teaching Math in 2010:
El hachero vende una carga por $100. El costo de la
produccion es............