The Evolution of Math Teaching
- 1960s:
A peasant sells a bag of potatoes for $10. His costs amount to 4/5 of his
selling price. What is his profit?
- 1970s:
A farmer sells a bag of potatoes for $10. His costs amount to 4/5 of his
selling price, that is, $8. What is his profit?
- 1970s (new math):
A farmer exchanges a set P of potatoes with set M of money. The cardinality
of the set M is equal to 10, and each element of M is worth $1. Draw ten big
dots representing the elements of M. The set C of production costs is
composed of two big dots less than the set M. Represent C as a subset of M
and give the answer to the question: What is the cardinality of the set of
profits?
- 1980s:
A farmer sells a bag of potatoes for $10. His production costs are $8, and
his profit is $2. Underline the word "potatoes" and discuss with
your classmates.
- 1990s:
A farmer sells a bag of potatoes for $10. His or her production costs are
0.80 of his or her revenue. On your calculator, graph revenue vs. costs. Run
the POTATO program to determine the profit. Discuss the result with students
in your group. Write a brief essay that analyzes this example in the real
world of economics.