Maths teaching through the ages

Teaching Maths In 1950s
A logger sells a truckload of lumber for £100. His cost of production is 4/5 of the price.
What is his profit?

Teaching Maths In 1960s
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 Maths In 1970s
A logger sells a truckload of lumber for £100. His cost of production is £80.
Did he make a profit?

Teaching Maths In 1980s
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 Maths In 1990s
A logger cuts down a beautiful forest because he is selfish and inconsiderate and cares nothing for the habitat of animals or the preservation of our woodlands. He does this so he can make a profit of £20.
What do you think of this way of making a living?
Topic for class participation after answering the question: How did the birds and squirrels feel as the logger cut down their homes? (There are no wrong answers, and if you feel like crying, it's ok.)

Teaching Maths In 2008
Handlowiec drewna sprzedaje *truckload* drewna dla GBP100. Jego koszt (oceniony) produkcji by GBP80.
Zrobia‚ on wyrabiaja… korzya?