World Population from 10,000BC to 2100AD (number notation, years to next billion and doubling)

Tracking the world population has always been a fascination for me. I particularly enjoyed the billion benchmarks reached for 4, 5, 6, and 7 billion during years 1974, 1987, 1999, and 2011, respectively. Your children will experience the 8 billion benchmark in about 6 years (2023). 

They can track the world population by going to the United Nations link http://www.worldometers.info/world-population/

This website has other fascinating data by country, by developed and developing, growth rates, population per square mile of space, etc.

We had a great conversation about why the population meter is growing every second and then looked at birth and death rates. The children noticed that the birth rate was more than twice as fast as the death rate. We even looked at the net increase in population during our one hour class and concluded that about 7,000 people were added, so next week we will have another 1.2 million more humans on the planet.

When I started analyzing the time it took for our world to add its first billion people and calculated 10,000 (for the BC data starting at 2 million) and added 1804 (when we reached the first one billion), I noticed that it took 11,804 years. From 1804 to 1927 when we reached 2 billion took only 123 years, then 33 years, 14 years, 13 years then the next three benchmarks took and/or are projected to take 12 years. Continuing into the projected future at a growth rate of 1.1%, from 8-9 billion they are projecting 15 years, from 9-10 billion 18 years and then 31 years from 10-11 billion. 

We discussed this phenomenon as being good news for the planet given limited resources such as land, food and water. We also discussed the reasons for these trends. The most interesting discussion was around why population growth rates in developing countries are so much greater than in developed countries. From the children’s perspective, we have better health care and economic stability so we should have higher growth rates. Of course, the opposite is true because education and low population growth has a strong correlation.

I challenged the children to also look at the number of years for the population to double, from 1-2 billion, from 2-4, 3-6, 4-8, 5-10, and so on. They can also look at the historical data from BC where it may have taken 2000 years for the population to double from 2.5 million to 5 million.

I had all the children including the K/1 class, convert number word notation (1.34 billion) to standard notation with digits only (1,340,000,000) and encouraged some of the older children to see how scientific notation works (1.34 x 10^9). To keep the scientific notation simple, when they were translating 203.34 million, I had them write 203.34 x 10^6 instead of the simplified scientific notation of 2.0334 x 10^8.

Finally, I had fun creating another column on pages 5 and 6 of the pdf that spoke to historical significance of the period. For example, 1750 (the industrial revolution), 1920 (women’s suffrage). I struggled with some of these periods like 1970 so I just called it the Disco era and Kramer’s first car. I leave it to you to discuss each of these eras and their significance such as the world wars and the end of the Cold War.

Enjoy.