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# Mixed Number and Fraction Estimation

## Estimating sums and differences

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Practice Mixed Number and Fraction Estimation
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Bubonic Plague

Credit: Pieter Bruegel the Elder
Source: http://commons.wikimedia.org/wiki/File:Thetriumphofdeath.jpg

It came from the East and swept across Europe. It spared no one. Wealthy and poor, foolish and wise, they all fell before it. When the pandemic was over, famine began. The Black Death, a 14th-century outbreak of the bubonic plague, had altered the course of history.

#### Fleas, Rats, and Death

Historians estimate that the Black Death killed between \begin{align*}\frac{1}{3}\end{align*} and \begin{align*}\frac{3}{5}\end{align*} of the population of Europe during the Late Middle Ages. It killed \begin{align*}\frac{1}{4}\end{align*} of the people living on Earth during the years it ravaged Asia and Europe. These enormous losses impacted society. At first, there was famine. The feudal system that defined medieval society depended on large numbers of peasants: peasants farmed the land that belonged to the nobility and provided food for the middle and upper classes. After the pandemic, there were not enough farmers, so there was not enough food. Peasants grew wealthier and gained freedom, because their work was suddenly valuable. Skilled tradesmen were also in great demand after the plague. Wealth that had been concentrated in the hands of a few nobles began to spread to other social groups.

Credit: Pemelet
Source: http://commons.wikimedia.org/wiki/File:Ratte-Vache.jpeg

During the Black Death, rats carrying infected fleas were responsible for spreading the plague from city to city and port to port. The plague returned to Europe many times, but later outbreaks were milder. Scientists believe that people grew increasingly resistant to it over time. The bubonic plague remains with us today. In the United States, about 7 people a year contract the plague. Today, however, the disease is easily treatable with antibiotics. We don’t need to fear another plague epidemic like the one that devastated Europe, but precautions are still taken against potential outbreaks of a disease that once destroyed \begin{align*}\frac{1}{4}\end{align*} of the Earth’s population.

See for yourself: http://www.bbc.co.uk/news/world-asia-23464195

#### Explore More

Watch the videos below to learn more about the impact of the Black Death, the origins of the pandemic, and the disease’s terrifying symptoms.