# How Large is a Ton of Rock?

#### Summary

One of a collection of PowerPoint/Excel modules designed to reinforce quantitative skills in geologic context. Students build a spreadsheet to calculate the edge length of cubes and diameter of spheres of various rocks weighing a ton. The rocks include ice, vein quartz, gabbro, granite and porous arkose. The calculation starts with the abundance and density of the minerals composing the rocks.

## Learning Goals

Students will:

- Gain experience in figuring out how to solve a problem starting with weight and density and asking for volume.

- Gain experience in figuring out a problem involving weighted averages in various contexts.

- Have worked with the concept that the bulk physical properties of a rock are related to the physical properties of its minerals

- Consider the effect of density on the volume of geometric bodies of the same weight.

- Consider the contribution of porosity to the bulk density of rock.

- Gain experience in figuring out how to solve a problem starting with weight and density and asking for volume.

- Gain experience in figuring out a problem involving weighted averages in various contexts.

- Have worked with the concept that the bulk physical properties of a rock are related to the physical properties of its minerals

- Consider the effect of density on the volume of geometric bodies of the same weight.

- Consider the contribution of porosity to the bulk density of rock.

## Context for Use

This activity was designed for an upper-division math-in-geology course for geology majors but can easily be used in an introductory undergraduate geoscience class, as well as a high school algebra class.

## Description and Teaching Materials

module (Acrobat (PDF) 397kB Jun28 06)

## Teaching Notes and Tips

The module is intended as a stand-alone resource. It can be used as a lab exercise or handwork assignment, or as the basis of an interactive classroom activity with just-in-time teaching of mathematical problem solving. The problem context and the mathematical content are developed within the module.

## Assessment

The module ends with hand-in questions that the students answer by manipulating the spreadsheets that they prepared while working through the module.