Basic HTML Version
© 2014 Pacific Crest
53
A
re You Ready?
Before continuing, you should be able to ...
I can...
OR
Here’s my question...
identify the unit(s) associated with a
presented number
determine key characteristics of the
context where the number is presented
predict what I think a number should be
use estimation to decide if a number is
reasonable
P
lan
Strategy for completing this activity
1. Do a quick search on your smart phone, computer, or another tool to find three examples of numbers
that strike you as difficult to understand.
2. Review the models for misuse of numbers.
3. Find three examples of numbers being used correctly, but in a way that would likely mislead an
audience (i.e., used to capitalize on an audience’s lack of number sense).
4. Answer the Critical Thinking Questions.
5. Produce three key discoveries about building number sense.
6. Complete the remainder of this activity (from Demonstrate Your Understanding through Assessing
Your Performance) on your own, or as directed by your instructor.
M
odel(s)
Exemplars and representations
How Much Sense Do the Numbers Make?
References for each model are available on the companion website.
M
odel
1: G
etting
F
aster
Getting Faster:
A 2004 paper in the journal “Nature” analyzed athletes’ Olympic performances in
the 100-meter dash and found that both male and female sprinters were getting faster. By charting
each group’s progress on a line, at some point the two lines would cross – with women matching and
then surpassing men around the year 2156.
This is very impressive until you continue the analysis. Plotting forward at a constant rate of change
(the slope of the line) means that somewhere around the year 2600, women will run fast enough to
break the sound barrier. We have numbers but not a lot of sense here.
1.5 Number Sense