This document defines key terms related to population: population refers to the people living in a country. The birth rate is the number of births per 1000 people in a year, while the death rate is the number of deaths per 1000 people in a year. Natural increase occurs when the birth rate is higher than the death rate, while natural decrease occurs when the death rate is higher than the birth rate. Formulas are provided to calculate birth rate, death rate, and natural increase or decrease.

1. Population
Lesson 1- Definition of population,
Birth Rate, Death Rate and
Natural Increase/Decrease

2. What is Population?
• Population is the people who live in a country.

3. Terms To be Remembered
• Birth Rate - The number of babies born per every
1000 people in the country in a year.
• Death Rate - The number of death for every 1000
people in the country in a year.
• Natural Increase - Occurs when the B.R is higher
than D.R.
• Natural Decrease – Occurs when the D.R is
higher than B.R.

4. Formula to calculate Birth Rate.
• (Number of Birth/Total Population) * 1000
• E.G. In a country with total population of
20,000 had 180 births in 2008. Calculate Birth
Rate.
• (180/20000)*1000

5. Formula to calculate Death Rate
• (Number of Death/Total Number of Population)
* 1000
• E.G. In a country with a total population of
40,000 had 400 births in 2010. Calculate the
death rate.
• (400/40000)*1000

6. Calculate Natural Increase or
Decrease.
• Natural Increase = B.R – D.R
• IF the B.R is more than D.R
• Natural Decrease = D.R – B.R
• IF the D.R is more than B.R
• IF BOTH Birth Rate and Death Rate is
EQUAL, it means Zero Growth or Optimum
Population