
Name_________________________
STUDENT INSTRUCTION AND ANSWER
SHEET
Activity 2: Concept
IntroductionMaking Complex Estimates
There are many instances in science where estimation is much more useful
and efficient than counting. In particular, estimation techniques are
important when analyzing a system for which counting is not actually possible.
Complete the following estimation task.
PREDICTION: How many females
in the 9th grade with long hair are scheduled to be at lunch between 12:15
and 12:30 and are eating in the cafeteria and having frenchfries with
ketchup? __________________
TASK: To check your prediction,
complete the following table by estimating the:
Variable

Estimated
Value 
Notes

n
 total number of students in your school



ff
fraction of females in your school



ff,9
 fraction of those females in 9th grade 


ff,9,L
 fraction of those females in 9th grade with long hair 


ff,9,L,t
 fraction of those females in 9th grade with long hair at lunch between
12:15 and 12:30 


ff,9,L,t,c
 fraction of those females in 9th grade with long hair at lunch between
12:15 and 12:30 in the cafeteria 


ff,9,L,t,c,FF
 fraction of those females in 9th grade with long hair at lunch between
12:15 and 12:30 in the cafeteria eating frenchfries 


ff,9,L,t,c,FF,k
 fraction of those females in 9th grade with long hair at
lunch between 12:15 and 12:30 in the cafeteria eating frenchfries
with ketchup 


F
 Fraction Of Total Population
(the product of all the fractions)



T
 Number of People at Your School Meeting The Criteria (product of
fraction of total population F, and the total school population,
n) 


CLASS AVERAGE, Tavg



Reflection
Questions about the Lunchroom Equation
T = n x ( ff x ff,9 x ff,9,L
x ff,9,L,t x ff,9,L,t,c
x ff,9,L,t,c,FF x ff,9,L,t,c,FF,k
) = n x (F)
A. What value of T did you determine and how did it compare with the class
average?
B. Give specific reasons why your value was different than the class average.
C. Predict how the calculation will change if you observe males instead
of females. Check your prediction by performing the necessary calculation.
D. Explain how the value of T would be different if you changed your definition
of long hair. Provide an example calculation with your written explanation.
E. Suppose that you were making this estimate for an allfemale school
where lunch is served from 12 to 1 pm. How would your estimate change?
Why?
