Which had more electric cars, Europe or the United States?

Grade level: 3rd – 5th grades

Skills: Bar graphs

Related environmental issues: Energy /  Air / Climate Change


The number of electric cars on the road has been significantly increasing.  There were over 7 million electric cars running in the world by the end of 2019. The table below shows where and how many electric cars are running in the world in 2019.


Screen Shot 2020-06-04 at 11.22.59 AM


  1. Which region had the most electric cars in the world?
  2. Which region had more electric cars, the United States or Europe?
  3. How many electric cars were running in the United States in 2019?



International Energy Agency, Electric Vehicles on Track


Answer keys

1. China
2. Europe
3. 1.5 million cars


Factual 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 uniformed decisions and ultimately help develop their critical thinking skills. (Read more)

Screen Shot 2020-04-02 at 10.20.25 AM


Screen Shot 2020-04-02 at 10.31.32 AM

Screen Shot 2020-04-02 at 10.31.38 AM


Published: March 26, 2020

Price: $6.25

How are we protected from dangerous air pollution?

Grade level: 4th – 6th grades

Skills: Place value (whole numbers)

Related environmental issues: Air

Clean air is essential for our health.The United States has protected Americans from dangerous air pollution that cause asthma, lung diseases, and early death by enacting the law called the Clean Air Act. It is estimated that the Clean Air Act will save at least 230,000lives by 2020 in this country.


  1. What digit is in the tens place of 230,000?
  2. What place is the 3 in 230,000?
  3. How many thousands are in this number?
  4. How many hundreds are represented by the 2?
  5. How many ones are represented by the 3?
  6. Which number represents 230,000?
a.23  x 102
b.23 x 103
c.23 x 104
d.23 x 105


Source: U.S. EPA, Clean Air Act Overview.

Photo: WWF


Answer keys

2.Ten thousands




The 225 Math Quizzes That Will Make You An Environmental Expert (2019) is available from Amazon.com.  (paperback)

Screen Shot 2019-01-26 at 10.54.15 AM



About this book>>>

Table of Contents >>>

Sample Quizzes >>>

Answer Key >>>