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 1996:
By laying off 402 of its loggers, a company improves its stock price from $80 to $100. How much capital gain per share does the CEO make by exercising his stock options at $80. Assume capital gains are no longer taxed, because this encourages investment.

Teaching Math in 1997:
A company outsources all of its loggers. They save on benefits and when demand for their product is down the logging work force can easily be cut back. The average logger employed by the company earned $50,000, had 3 weeks vacation, received a nice retirement plan and medical insurance. The contracted logger charges $50 an hour. Was outsourcing a good move?