# Cardinality Jokes

## A History of Math Education

Saw this one on a professor's door:
The evolution of mathematics education
during the last 30 years.
1960's
A peasant sells a bag of potatoes for \$10. His costs amount to 4/5 of his
selling price. What is his profit?
1970's
A farmer sells a bag of potatoes for \$10. His costs amount to 4/5 of his
selling price, i.e. \$8. What is his profit?
1970's (New Math)
A farmer exchanges a set P of potatoes with a set M of money. The cardinality
of the set M is equal to \$10 and each element of M is worth \$1. Draw 10 big
dots representing the elements of M.
The set C of production costs is comprised of 2 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? (Draw everything in red).
1980's
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 more...

## The History of 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 of M 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 more...

## The Evolution Of A Math Problem

1950:
A lumberjack sells a truckload of lumber for \$100. His cost of production is 4/5 of this price. What is his profit?

A lumberjack sells a truckload of lumber for \$100. His cost of production is 4/5 of this price, or in other words \$80. What is his profit?

1970 (new math):
A lumberjack exchanges a set L of lumber for a set M of money. The cardinality of set M is 100, and each element is worth \$1. Make 100 dots representing the elements of set M. The set C is a subset of set M, of cardinality 80. What is the cardinality of the set P of profits, if P is the difference set MC?

1980 (equal opportunity math):
A lumberjack sells a truckload of wood for \$100. His or her cost of production is \$80, and his or her profit is \$20. Your assignment: Underline the number 20.

1990 (outcome based education):
By cutting down beautiful forest trees, a lumberperson makes \$20. What do you think of his way of more...

## SAT score decay

SAT score decayAs we all know SAT scores have been on the decline for years.The following may be the reason why.A math problem in the 60'sA logger sells a truckload of lumber for \$100. His cost of production is four-fifths of this price. What is his profit? A math problem in the 70'sA logger sells a truckload of lumber for \$100. His cost of porduction is four-fifths of this price, or \$80. What is his profit? A math problem in the 70's using New MathA logger exchanges a set L of lumber for a set M of money. The cardinality of set M is 100, and each element is worth \$1. Make 100 dots representing the elements of set M. The set C of the cost of production contains 20 fewer points than set M, and answer the following question: What is the cardinality of the set P of profits? A math problem in the 80'sA logger sells a truckload of wood for \$100. His cost of production is \$80, and his profit is \$20. Your assignment: underline the number 20.A math problem in the 90's under Outcome Based more...

## 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 more...