### Summary

Students will analyze data of tornadoes throughout the United States. They will create a bar graph of the number of tornadoes for the top ten states in the country and then calculate the median and the mode of the data.### Engineering Connection

Engineers of all disciplines organize data into tables and graphs to help them better understand problems and formulate solutions. Engineers use computers to analyze and graph tornado and storm data, which helps them design better warning systems and predict occurrence patterns. Some civil engineers also prototype and test construction methods and materials so new structures are sturdier and safer in a tornado.

###
Educational Standards
Each *TeachEngineering* lesson or activity is correlated to one or more K-12 science,
technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in *TeachEngineering* are collected, maintained and packaged by the *Achievement Standards Network (ASN)*,
a project of *D2L* (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; *e.g.*, by state; within source by type; *e.g.*, science or mathematics;
within type by subtype, then by grade, *etc*.

Each *TeachEngineering* lesson or activity is correlated to one or more K-12 science,
technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in *TeachEngineering* are collected, maintained and packaged by the *Achievement Standards Network (ASN)*,
a project of *D2L* (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; *e.g.*, by state; within source by type; *e.g.*, science or mathematics;
within type by subtype, then by grade, *etc*.

###### Next Generation Science Standards: Science

- Analyze and interpret data on natural hazards to forecast future catastrophic events and inform the development of technologies to mitigate their effects. (Grades 6 - 8) Details... View more aligned curriculum... Give feedback on this alignment...

###### Common Core State Standards: Math

- Draw a scaled picture graph and a scaled bar graph to represent a data set with several categories. Solve one- and two-step "how many more" and "how many less" problems using information presented in scaled bar graphs. (Grade 3) Details... View more aligned curriculum... Give feedback on this alignment...
- Summarize numerical data sets in relation to their context, such as by: (Grade 6) Details... View more aligned curriculum... Give feedback on this alignment...
- Reporting the number of observations. (Grade 6) Details... View more aligned curriculum... Give feedback on this alignment...
- Describing the nature of the attribute under investigation, including how it was measured and its units of measurement. (Grade 6) Details... View more aligned curriculum... Give feedback on this alignment...
- Giving quantitative measures of center (median and/or mean) and variability (interquartile range and/or mean absolute deviation), as well as describing any overall pattern and any striking deviations from the overall pattern with reference to the context in which the data were gathered. (Grade 6) Details... View more aligned curriculum... Give feedback on this alignment...
- Relating the choice of measures of center and variability to the shape of the data distribution and the context in which the data were gathered. (Grade 6) Details... View more aligned curriculum... Give feedback on this alignment...

###### International Technology and Engineering Educators Association: Technology

- Various relationships exist between technology and other fields of study. (Grades 3 - 5) Details... View more aligned curriculum... Give feedback on this alignment...

###### Colorado: Math

- Draw a scaled picture graph and a scaled bar graph to represent a data set with several categories. (Grade 3) Details... View more aligned curriculum... Give feedback on this alignment...
- Give quantitative measures of center (median and/or mean) and variability (interquartile range and/or mean absolute deviation), as well as describing any overall pattern and any striking deviations from the overall pattern with reference to the context in which the data were gathered. (Grade 6) Details... View more aligned curriculum... Give feedback on this alignment...

###### Colorado: Science

- Develop and communicate an evidence-based scientific explanation for changes in weather conditions (Grade 5) Details... View more aligned curriculum... Give feedback on this alignment...

### Learning Objectives

After this activity, students should be able to:

- Explain why engineers need to know where tornadoes occur and how engineers might analyze data to determine those patterns.
- Be able to rank states according to the number of tornadoes (greatest to least).
- Explain the difference between and how to calculate the median and the mode.
- Create bar graphs and interpret data of tornado occurrences.

### Materials List

Each group should have:

- Ruler
- Graph paper
- Pencils
- Markers, crayons, or colored pencils
- Calculator
- Copy of either the Ranked Worksheet (easier) or the Alphabetized Worksheet (advanced)

### Introduction/Motivation

The United States, on average, experiences about 1,000 tornadoes a year. They can range from a few feet to more than a mile in diameter and can travel distances from a few hundred feet to many miles.

In the United States tornadoes occur with the highest intensity and highest frequency in a region called 'Tornado Alley.' This region, which is located east of the Rocky Mountains, covers all or parts of the following states: Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Louisiana, Mississippi, Missouri, Nebraska, Oklahoma, South Dakota and Texas. However, tornadoes can occur in each of the 50 states.

Engineers work to build structures that better withstand the strong winds of a tornado, especially in those states where tornadoes occur most frequently. They also collect and analyze data to better understand tornadoes so that they can better predict where they will occur and how damaging they might be.

In this activity, we will look at the number of tornadoes that has occurred in each state during the period 1950-1994. We will analyze some of these data and represent them in various forms.

### Procedure

Before the Activity

- Decide if the students will work with the Ranked Worksheet or the Alphabetized Worksheet tables. (Note: the ranked data will be easier, whereas the alphabetized data will provide an extra challenge.)
- Copy the tables for each student.

With the Students

- Explain to the students that tornadoes can form in any state and that they will be looking to see which states have the most and least tornadoes.
- Ask students to predict which states they think will have the most and least tornadoes. What about their home state? Alaska? Hawaii? Students should write their prediction in their science journals or on a sheet of paper.
- Have the students get into pairs. Pass out either the Ranked Worksheet or the Alphabetized Worksheet to students.
- Have students create a bar graph of the ten states with the most tornadoes.
- Have students create a bar graph of the ten states with the least tornadoes.
- Which state actually has the most? (Answer: Texas) Which state has the least? (Answer: Alaska) Where there any surprises? Have students write the answer on their worksheets.
- Explain to students that the median is the middle value of a series of numbers, and mode is the number that occurs the most often.
- Have students find the median and the mode of the data set and record their values on their worksheets. Providing students with a ranked data set will be very helpful for this part. (The median will be between the 25th and 26th, ranked states, Wyoming and South Carolina respectively. The exact answer would be 428.5, but anything between 423 and 434 could be acceptable.) The mode is 886.
- Have the students look at their original predictions (what states they think will have the most and least tornadoes). Was their prediction right? How close were their predicted states to the median and mode of the data?
- Using engineering terms, have students write a summary of the data they graphed. Tell them to write a paragraph summarizing what the graphs tell them. This should be 3-4 sentences describing any patterns they see, the median and mode of the data, and why understanding the data is important to engineers.

### Attachments

### Troubleshooting Tips

Make sure students clearly understand what median and mode are.

Calculators will probably be necessary to calculate the mean of the data.

### Assessment

Pre-Activity Assessment

*Prediction:* Have students predict which states have the most and fewest tornadoes. Have them write their answers down in their science journals or on a sheet of paper.

Activity Embedded Assessment

*Worksheet/ Pairs Check:* Have students work individually or in pairs on their worksheet. Students who work in pairs should check each other's answers.

Post Activity Assessment

*Prediction Revisited:* Have students review which states have the most and fewest tornadoes. Have them look at their predictions in their science journals or on a sheet of paper. Were they right?

*Graphing:* Students should create a bar graph of the ten states with the most number of tornadoes. Students then create a bar graph of the ten states with the least number of tornadoes.

*Engineering Analysis:* Have students write an engineering analysis of the data they graphed. Tell them to write a paragraph summarizing what the graphs tell them. This should be 3-4 sentences describing any patterns they see, the median and mode of the data, and why understanding the data is important to engineers.

### Activity Extensions

For more math extensions, have students use the Alphabetized Worksheet and put all 50 states in ranked order.

Have students research tornado activity in their own state.

The following website has state-specific information about tornadoes, including annual averages of tornadoes and averages of very strong tornadoes by state. http://www.ncdc.noaa.gov/oa/climate/severeweather/tornadoes.html

For advanced students: Calculate the average number of tornadoes in the top ten states for a given year (students should find the average of the top ten states and than divide that number by 45 because data is for 45 years).

### References

### Contributors

Jessica Todd; Melissa Straten; Malinda Schaefer Zarske; Janet Yowell### Copyright

© 2004 by Regents of the University of Colorado.### Supporting Program

Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder### Acknowledgements

The contents of this digital library curriculum were developed under a grant from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and National Science Foundation GK-12 grant no 0338326. However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

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