从一道数学题看美国的终衰
Follow the deterioration of our culture and educational system for the 63 
Years from 1957-2020
1.  Teaching Math 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?
2.  Teaching Math 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?
3.  Teaching Math in 1970s
A logger sells a truckload of lumber for $100. His cost of production
is $80. Did he make a profit?
4.  Teaching Math 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.
5.  Teaching Math 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.)
6.  Teaching Math in 2000s
If you have special needs or just feel you need assistance because of
race, color, religion, sex, age, childhood memories, criminal background,
then don't answer and the correct answer will be provided for you.
There are no wrong answers.
7.  Teaching Math in 2020:[撇嘴][撇嘴]
Un hachero vende una carrtada de madera para 100 pesos. El costo de la
producciones es 80 pesos. Cuanto dinero ha hecho?