Summary

In this activity students will work cooperatively to solve conversion based problems using dimensional analysis. Students are required to independently determine an answer for each question and be able explain their method of solving with their peers. This activity is designed to allow students to work at their own pace, and for students to take on a teaching role by communicating their understanding with their peers.

Grade Level

Middle School or High School

NGSS Alignment

This activity will help prepare your students to meet the performance expectations in the following standards:

• HS-PS1-7: Use mathematical representation to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.
• Science and Engineering Practices:
  • Using Mathematics and Computational Thinking

Objectives

By the end of this activity, students should be able to

• Convert between units of measurement using dimensional analysis.
• Use dimensional analysis for mass, length, volume, temperature, and density unit conversion problems.
• Understand the purpose of using dimensional analysis for converting between units of measurement.

Chemistry Topics

This activity supports students’ understanding of

• Quantitative Chemistry
• Dimensional Analysis
• Measurement

Time

Teacher Preparation: 10 minutes

Lesson: 45-60 minutes

Materials

Per Student:

• Small white board
• Calculator
• Conversion sheet
• Dry erase marker

Per Group:

• Dry erase board erasers
• Task Cards
• Answer Sheet

Safety

• No specific safety precautions need to be observed for this activity.

Teacher Notes

• This is a cooperative learning activity to use in your classroom after you have taught dimensional analysis or converting units.
• This activity gets all students involved and gives them an opportunity to practice their newly acquired skill. Students will be placed into small groups of three to five students and will be given a set of task cards.
• Each student needs a small white board, marker, calculator and conversion sheet (provided).
• Print sets of 20 task cards from the attached PowerPoint file and cut them out into individual questions. Each group needs one set of task cards, and one answer sheet.
• Have students place the task cards in the middle of the table.
• Pick a “Leader” of the group (ex: person wearing the most blue). This role will alternate throughout the activity.
• The first Leader flips over the top card and reads the problem or question aloud.
• Everyone solves the problem using dimensional analysis and answers the question on their white board individually, including the Leader.
• Students place their dry erase boards face down when finished.
• When the Leader notices everyone is done the Leader says “Showdown!” and everyone flips over their boards to show and compare answers.
• The group must come to an agreement on an answer to the problem, make sure to explain to students the importance of discussing answers that are different. Let them know to ask for help if they can’t agree on the answer.
• The Leader for that question then records the group’s agreed upon answer on the answer sheet.
• The Leader passes the answer sheet to the person on their right, and that person is now the Leader for the next question. The Leader role rotates for each round and students continue working as time allows.
• The teacher should be floating around monitoring each group and looking for those that might need help.
• Collect the answer sheets from each group at the end of the activity.
• An answer key has been provided for download for teacher reference. Please notes that calculations and final answers are not completed using significant digits!