Teachers TryScience

1. Show short video preview from NOVA: World in the Balance. Ask students their initial thoughts on how wealth or lack of affluence affects population. (developed vs. undeveloped, third world).  Mention rural communities, immigration, and poverty index.  Name some countries that have been in the news and compare the economies of those countries to the United States.
2. Introduce population profiles. Now would be a good time to show the attached Population Pyramids Presentation to review population ideas.
3. Project a population pyramid example on the board:  X-axis is the population; Y-axis is the age ranges, and divider separates male and females.  Focus and explain one population profile and how it can be used to project future populations.
4. Review the formula to determine population growth: (Pert) (t=future year)

P_{t  (population at time t)} = P_{o( initial population)}e^{r t  (growth rate x time)}

1. Determine rate instead of population.   Or determine the time if all other given.
2. Practice a Pert problem with the class. To grow exponentially means that the topic being studied is increasing in proportion to what was previously there

Project the world population in 2017 given the 1997 mid-year population of 5.85 billion and a growth rate of 1.36% per year.

N = N₀ (e)^kt
N = (5.85 x 10⁹) x e^{(0.0136 x 20)}
N = 7.679 x 10⁹ 
The population in 2017 will be 7.679 billion.

1. Split the class in two, each solving for a different part of the formula and have each answer a different country.  Go over the problems with the class. 

Mexico growth rate: 1.13%; population 111,211,789

Spain growth rate: 0.072%; population is 40,525,002

1. Assign students (groups of 2) countries (in different transitions) or have them choose their own.  However, no two groups should have the same country and all countries should be evenly split, in terms of affluence and third world.
2. Students will have to fill out the attached Age Structure Pyramids Worksheet and produce their findings in a presentation, including a completed Population Pyramid, by the end of the week.  Final presentations should have population projections 50 years from now using the Pert formula.