Mathematics and Population

Beniel Seka

One day, when I was in Form One at Old Moshi Secondary School our teacher of English language took us to the school library. Her name was Mrs Laing from Canada. She was also a teacher in charge of the library.

After a brief introduction about the library and its services, she allowed us to pick a book of interest and read. I picked a book called Mathematics for the Million. When she passed around, she found me holding the book. “Wow, mathematics for the million!” she remarked. She took the book and opened a few pages. She handed it back to me and said,”Congratulations.”

I did not know why she congratulated me but, I learned later that she was also a mathematics teacher. She knew that I had chosen an interesting book because she liked mathematics. One of my school mates told me that she taught them the compound interest formula which is applied in calculating population estimates

On World Population Day in March this year (2012), my son John, an advocate who works with the Tanzania Women’s Bank wrote to me the following message: ‘Today, the world population has reached seven billion. You can write a features article to show how mathematics is involved in population’.

 He had seen how I related mathematics with love and thought I could do the same with population. I had said that love is like mathematics: It adds your pleasure; it subtracts your frustrations; it multiplies your wealth; it squares your peace and it divides your emotions.

“Yes,” I said to myself. “One day I will do it. I thought of how statistics is involved in population. We can calculate means and standard deviations. After population census a lot of statistics will be involved in processing the census data. Statistics is a branch of mathematics. Percentages are also used to a great extent in making population predictions.

The population census in Tanzania has been scheduled to take place in Tanzania on 26^th August 2012. Data collectors have been trained to collect accurate data that will be used to make plans for Tanzania’s future as well as providing information to the world statistics. For example, projections based on prediction made after the last census may be checked. To what extent the predictions were accurate will be revealed by the real data.

In making the predictions, life expectancy, mortality rates and demographics are used. For example, demographic data available in 2012 shows that the global sex rate is approximately 1.01 male to 1 female.  All these use to a great extent, mathematical formulae and techniques. The compound interest formula is a typical example.

The world population has experienced continuous growth since the end of the ‘great famine’ and the ‘black death’ in 1350 when it stood at around 370 million. It is estimated that the world population reached one billion for the first time in 1804.  In1960 it reached three billion. It reached four billion in 1974 and five billion in 1987. However, in 1999 it reached six million.

It is worth noting that in the modern era, during the industrial and agricultural revolutions, the life expectancy increased drastically. For example it is said that the percentage of children born in London who died before the age of 5 years decreased from 74.5% in the period of 1739-1749 to 31.8% in 1810-1829.

Many countries in the developing world have experienced rapid population growth over the past century. For example, China’s population rose from approximately 430 million in 1950 to 590 million in 1953 and now stands at 1.3 billion.

According to the 2008 world population figures, the country with the highest population is China which recorded 1.33 billion living humans. The top ten populous countries in that year, with figures in brackets are as follows:

1.    China (1.33 billion)

2.    India (1.14 billion)

3.    USA (304 million)

4.    Indonesia (228 million)

5.    Brazil (102 million)

6.    Pakistan (165 million)

7.    Bangladesh (160 million)

8.    Nigeria (151 million)

9.    Russia (142 million)

10.                Japan (128 million)

The day of seven billion was declared by the population Division of the United Nations Organisation to be October 2011. How does Tanzania compare its population statistics with other countries? This is the question that will be answered after calculations have been made. Mathematics will be used, will it not?

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