What products did Americans buy more amid the Coronavirus outbreak?

Grade level: 5th – 6th grades

Skills: Percentage and bar graph

Related environmental issues: Others

Amid the Coronavirus outbreak,  people started rely more on online shopping.  A research showed that daily online grocery sales doubled in a month.  Also, sales of some products such as canned goods, home fitness products, flu medicines, hand sanitizer, and toilet paper increased significantly. The bar graph below shows by what percentage sales of those products increased over the last month in the United States. For example, sales of home fitness products increased by 55%.

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  1. Among those produces, sales of which product increased the most?
  2. The average American buys $4 of canned goods in a month. How much of canned goods in dollars did the average American buy over the last month? Round to the nearest whole number.
  3. The average American buys 12 rolls of toilet paper in a month. How many rolls of toilet paper did the average American buy over the last month? Round to the nearest whole number.



Note: Monthly per capita canned food sales was sought by [total sales / population/12](5.2+3.9+2.7+2+2+0.8)/0.327=$51/year  51/12=4.25

Source: Forbes, (March 31, 2020). E-Commerce Up 25%, Online Grocery Shopping Up 100%, Virus Protection Products Up 807%.

Barron’s, (March 31, 2020). Sales of PCs and Dumbbells, Not Just Toilet Paper, Are Soaring, New Data Show.

Statista,Estimated canned food market value in the United States in 2017 and 2025, by product category. 

Statista, 2018. The U.S. Leads the World in Toilet Paper Consumption



Answer keys

1. hand sanitizer
2. $7 (4 x 0.87 = 3.48  4+3.48=7.48)
3. 40 rolls (12 x 2.31 = 27.72 12+27.72=39.72)


Factful Environmental Math Problems (2020)

Just published and now available from Amazon  (paperback)

About this book

The objective of Factful Environmental Math Problems is to cultivate our young people’s skills to analyze and evaluate fact-based data for understanding our world, while improving their math skills and critical thinking skills.

With the rise of the Internet and new technology, building skills to analyze and evaluate fact-based data becomes increasingly important for our young people to prepare for this rapidly changing world. These skills minimize their chances of being brainwashed by false information and making uninformed decisions and ultimately help develop their critical thinking skills. (Read more)

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Published: March 26, 2020

Price: $6.25

How many more wild giant pandas do we have now?

Grade level: 6th – 8th grades

Skills: Percentage

Related environmental issues: Biodiversity & Deforestation

[The use of a calculator is permitted]

Giant panda has long been on the endangered species list because the forests they live in China have been destroyed as the population in the country grows. However, due to conservation efforts made by the Chinese government, wild panda numbers have been increasing. The pandas are still at risk but they are now off the endangered species list.

According a survey, there are 1,864 giant pandas in the wild, and the population has grown by 16.8% over the last decade.  The survey also found that 66.8% of wild giant pandas live within protected panda nature reserves in China, while the rest live outside of the protected areas.


  1. How many wild giant pandas were there 10 years ago? How many more giant pandas do we have now? Round to the nearest ones.
  2. How many giant pandas live outside of the protected panda nature reserves? Round to the nearest ones.


Source: WWF, 2015. Panda population grows nearly 17 percent

Photo: WWF


Answer keys

  1. There were 1,596  pandas ten years ago. The population increased by 268 [116.8/1864 = 100/X]
  2. 619       [1,864 x (1 – 0.668)]