Tools  Math 'Plausible Estimation' Estimates for the USA Tasks, Set #4
Estimates for a Million, Set #1 (solutions)
Estimating for Amazing Facts: Set #2 (solutions)  Set #3 (solutions)
Estimates for the USA, Set #4 (solutions)
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.

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.
 Babies
How many babies are born in the USA in each minute?


Assumptions
 The population of the USA is approximately 270 million.

Reasoning

 Teachers
How many K8 Elementary School teachers are there in the USA?


Assumptions
 The population of the USA is approximately 270 million.

Reasoning

 Newspapers
How much is spent on newspapers in the USA each year?


Assumptions
 The population of the USA is approximately 270 million.

Reasoning

 Cars
How many cars are bought each year in the USA?


Assumptions
 The population of the USA is approximately 270 million.

Reasoning

 Dentists
How many dentists are there in the USA?


Assumptions
 The population of the USA is approximately 270 million.

Reasoning

Estimates for a Million, Set #1 (solutions)
Estimating for Amazing Facts: Set #2 (solutions)  Set #3 (solutions)
Estimates for the USA, Set #4 (solutions)
