Salt Marshes: estimation techniques using basic algebra and geometry

This page authored by Yelena Meadows (Upper Iowa University) & Sharareh Nikbakht (Appalachian State University)


In this lab activity students will read about some facts of salt marshes ecology and use real-life data to make estimations about fiddler crab colony population & food material consumption, practice calculations of measures of central tendency, work with proportions & percents, and use basic geometry to estimate volumes of water absorbed by the marshes due to fiddler crab colony activity.

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Learning Goals

Educates students about functions of, positive and negative economic importance of the salt marshes.

Engages students in civil discourse/ communications that lead to more effective decisions.

It advances student literacy around sustainability issues.

Encourages self-reflection and personal development of their voice for solving societal challenges

Critical thinking

Context for Use

Appropriate for a developmental math class as an in-class activity, a homework, or a group activity in a smaller class setting
No equipment necessary.
Appropriate as a quick review of basic math and word problem solving in college algebra, precalculus, or calculus class
Appropriate in general biology classes as a basic math skills pratice

Description and Teaching Materials

The students will use:

i) One page scientific text on ecology of salt marshes and fiddler crabs

ii) A sample of fiddler crab data (Figure 1, included in the document)

iii) A picture of fiddler crab's prosoma (shell) and how width and height were measured (Figure 2, included in the document)
iv) A picture of a 1 meter grid of burrows in a marsh environment (Figure 3, included in the document)

Math Skill Practice will be based on:
1) volume of a cylinder
2) definition of a mean (average)
3) ratio
4) proportion
5) percent Salt Marshes Math Lab with Answers (Acrobat (PDF) 654kB May17 14)

Teaching Notes and Tips

To make this activity interesting, you may want to check out the two websites included in the document and/or watch the NOAA Episode 124 (link included below) with your students


Each of the 25 skills practice questions has a range of possible answers. The key is provided for general guidance. Student work can be graded as percentage of 25 possible points.

Discussion questions are open ended and can take up a whole period and/or assigned as essays.

References and Resources