'Plausible Estimation' Estimating for
Amazing Facts Tasks - Set #2
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 estimate quantities to an appropriate
degree of accuracy
· choose suitable units for your estimate
· communicate the assumptions upon which your estimate is based.
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1. Heartbeats
How many times does a person's heart beat in a lifetime?
Assumptions
Reasoning
2. Crowded Tennis (or football)
How many people could comfortably stand on a tennis court? (or, if you prefer, a US football
field?)
Assumptions
Reasoning
3. Mummies
An unraveled toilet roll is 33 meters, or 100 feet long.
Will one toilet roll be enough to wrap a person?
Describe your reasoning as fully as possible.
Assumptions
Reasoning
4. The Train Journey
I met Dodge on an Amtrak train in Union Station, Washington, in January of 1993. He came into
an empty car and sat beside me, explaining that the car would before long fill up. It did. He didn't
know me from Chichikov, nor I him...Two hundred miles of track lie between Union Station and
Trenton, where I got off, and over that distance he uttered about forty thousand words. After I left
him, I went home and called a friend who teaches Russian literature at Princeton University, and
asked her who could help me assess what I had heard,...
How many words do you think you could speak, at normal conversation speed, during a 200 mile
train journey? (Hint: You could start by timing yourself reading the article).
Hence decide if the statement 'he uttered about forty thousand words' is reasonable.
Assumptions
Reasoning