'Plausible Estimation' Estimates
for the USA Tasks - Set #4
Malcolm Swan
Mathematics Education
University of Nottingham
Malcolm.Swan@nottingham.ac.uk
Jim Ridgway
School of Education
University of Durham
Jim.Ridgway@durham.ac.uk
The aim of this assessment is to provide the opportunity for you to:
· develop a chain of reasoning that will enable you to make reasonable estimates of facts
about the USA from population data
· communicate the assumptions upon which your estimate is based.
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Try to estimate reasonable answers to each of the following questions.
Describe carefully at each stage any assumptions you make.
Show, step by step how you arrive at your estimate.
Each estimate should use the following fact:
The population of the USA is approximately 270 million.
1. Babies
How many babies are born in the USA in each minute?
Assumptions
· The population of the USA is approximately 270 million.
Reasoning
2. Teachers
How many K-8 Elementary School teachers are there in the USA?
Assumptions
· The population of the USA is approximately 270 million.
Reasoning
3. Newspapers
How much is spent on newspapers in the USA each year?
Assumptions
· The population of the USA is approximately 270 million.
Reasoning
4. Cars
How many cars are bought each year in the USA?
Assumptions
· The population of the USA is approximately 270 million.
Reasoning
5. Dentists
How many dentists are there in the USA?
Assumptions
· The population of the USA is approximately 270 million.
Reasoning