Determining Density

Archimedes & the Case of the Missing Gold

The Basics of Density

Heating Up and Spreading Out

Is Putty or Clay More Dense?

Reading: Archimedes & the Case of the Missing Gold

Duration: Approximately 50 minutes

Instead of the normal SciGen script, this unit begins with an expert illustration retelling the classic story Archimedes' "EUREKA!" moment. He is credited by some for coming up with the idea of determining the volume of an irregularly shaped object by dipping it into water... just as he was dipping himself into the bathtub!

LEARNING OBJECTIVE

Students will learn about the procedure of measuring the volume of an irregularly shaped solid by the use of displacement. They will also begin to connect the property of density with the properties of mass and volume.

Teacher Tips

Think ahead about how you will assign the roles to read the comic aloud: as a class, in small groups, or individually. Note that students often willingly take on roles regardless of the gender of the characters.
While it is possible for the students to read the PDF of the comic online, we suggest printing it out for the students so they can hold it in their hands and mark it up as they read.
Prior to the reading the comic, explain to students that they will encounter new vocabulary terms and ideas that may not be familiar. Reassure them that this lack of familiarity is okay. The reading is meant to introduce the ideas, not explain them completely.
Review the focus words of the week. The focus word chart linked on the unit overview page should be used as a resource for students to review definitions and sample sentences.

Teacher Tune-ups

Teaching Notes

ACTIVITY OVERVIEW

Set the context: scams (10 minutes)
Engage with the comic (20 minutes)
Post-reading discussion questions: about the science (20 minutes)

Set the context: scams (10 minutes)

Ask students if they have ever been concerned that they bought something that did not live up to its promise.

In a relevant story, Archimedes of the ancient Greek city of Syracuse was called upon by the king because he was worried about a similar problem.

Discuss image one: the king had given the goldsmith one bar of gold with which to create a new crown. However, when the king gets the finished crown he grows concerned that he's been cheated.

Discuss image two: Archimedes presents an idea to the king. Obviously the king doesn't like the idea, but even so have the students explain why Archimedes might recommend melting down the crown.

Answer:

to compare the volume of a gold brick used to MAKE the crown to a gold brick MADE FROM the crown

Engage with the comic (20 minutes)

Have the students read the comic individually, in groups, or as a whole class. Be sure to stop frequently to check for understanding. Below are discussion questions that may be used by the teacher.