Density of the Earth - How to Solve It

Initial Publication Date: September 5, 2006 | Reviewed: October 31, 2012


This module addresses the problem of determining the density of the Earth and invites the student to figure out how to solve the problem. The module utilizes the four-step process developed by George Polya in his book How to Solve It in 1957: 1) Understanding the problem, 2) Devising a plan, 3) Carrying out the plan, and 4) Looking back. This module is the first in a series of six that examine the density of planets and rocks.

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Learning Goals

  • Instruct students in the four steps of Polya's problems solving strategy.
  • Use Polya's four steps to solve the question of what the density of the Earth is.

Context for Use

This module was designed to be used in an undergraduate mathematical geology class where students are asked to look at geological questions mathematically and may spend more time on the math than on the geology.

Description and Teaching Materials

This module is one of several developed by Dr. Vacher. The module presentation can be found at

The Powerpoint file is considered to be the student version. There is also an instructor's version that has active spreadsheets in it. There are instructions for requesting this version on the website.

Teaching Notes and Tips

These modules were developed as essentially self-paced, take-home lab assignments. Students are supposed to work through the modules, slide by slide, building their own worksheets as they go along, taking note of instructions and prompts, hints, and queries.

Students must have access to compters equiped with a spreadsheet program such as Excel.


The easiest way to test student work on this module is to ask students to hand in a copy of their worksheets starting with a different set of input data. The module also ends with homework assignment questions.

References and Resources