Quantitative Skills > Teaching Resources > Activities > How big is a billion?

Big Money: Intuition about big numbers using the national debt (and other governmental excess)

Jerry Johnson (compiled by Jennifer Wenner, University of Wisconsin-Oshkosh)

Department of Mathematics and Statistics, University of Nevada Reno, Reno, NV


This is an exercise designed to help students get their brains around big numbers using real world examples. The real-world examples are focused around money issues such as the national debt and budgeting. There are questions for students and some guidelines. These exercises are one of several that were produced for the National Numeracy Network under a grant from the Woodrow Wilson Fellowship Foundation through the National Council on Education and the Disciplines.

Learning Goals

Context for Use

This exercise is appropriate for an introductory course. It addresses such questions as "How big is a billion?" and "How much of the national debt is each citizen of the US responsible for?" It is appropriate for initiating discussion of the relative size of numbers and is a good lead into geologic age. Students have difficulty with a billion years but seem to be able to relate to a billion dollars. The exercise can be used as a homework assignment or an in class assignment where 2-3 students work on some of the questions.

For the last few questions, students will need to have a dollar bill. If you want more accurate numbers (those given are for the debt in 2002 - about 3/4 of what it is today (Feb 2005)), students can look them up using the websites given in the handout. However, this requires that students have access to the web while completing this exercise.

Teaching Notes and Tips

There are several pointers included in the instructors notes in the file below.

Teaching Materials

The exercise/activity Understanding Big Numbers (Acrobat (PDF) 21kB Oct29 04) that includes student activities and instructor notes.


This exercise can be collected and graded. The answers to each question are provided in the teaching materials.

Giving students a question about estimation or large numbers on the exam can also serve to assess the success of this exercise.

References and Resources

Teaching resources on the NNN Website.

Controlled Vocabulary Terms

Subject: Mathematics
Resource Type: Activities:Classroom Activity, Problem Set
Special Interest: Quantitative
Grade Level: College Lower (13-14):Introductory Level
Quantitative Skills: Geometry and Trigonometry, Arithmetic/Computation, Logarithms/Exponential Functions:Exponential Growth and Decay, Units and Unit Conversions, Problem Solving, Scientific Notation
Ready for Use: Ready to Use
Topics: Chemistry/Physics/Mathematics

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