How Math Was Taught in....

A fun story arrived via email a few days ago. I am translating it from Hebrew below.

A woman described her experience in a supermarket. She was buying produce worth $158, gave to cashier two $100 bills and was looking for $8 in her wallet to avoid change in small bills and receive just a $50 bill back. Young cashier hesitantly took the $8 and was clueless why it is given to her and what to do about it. They ended up calling a supervisor who patiently explained to the cashier the math of this transaction, while she stood there with a tears in her eyes not understanding what all these people want from her.

Coming home this woman contemplated what changed have happened in math education from the 50th to nowadays that has shaped attitude of students who became immune from any criticism by the teachers. She wrote:

This is how we taught math in the Fifties:
"A farmer sold a cart of oranges for $100. The cost of production of these oranges is 4/5 of the selling price. What is the farmer's profit?"

This is how we taught math in the Seventies:
"A farmer sold a cart of oranges for $100. The cost of production of these oranges is 80% of the selling price. What is the farmer's profit?"

This is how we taught math in the Eighties:
"A farmer sold a cart of oranges for $100. The cost of production of these oranges is $80. What is the farmer's profit?"


This is how we taught math in the Nineties:
"A farmer sold a cart of oranges for $100. The cost of production of these oranges is $80. What is the farmer's profit?"
Mark the correct answer:
() $20   () $40  () $60  () $80  () $100

This is how we taught math in the year 2000:
"A farmer sold a cart of oranges for $100. The cost of production of these oranges is $80. Farmer's profit is $20. Mark below if the last statement is:
() True    () False

This how we teach math now:
"A farmer sold a cart of oranges for $100. The cost of production of these oranges is $80. If you know how to read mark X next to the number $20 because this is the farmer's profit..."
() $20 () $40 () $60 () $80 () $100