- Created by: Paul Young, San Diego City College
- Type of activity: hands on activity
- Course level: Pre Algebra
- Topic: Ratios
- Materials: 1 bicycle with multiple gears, 1 yard stick per group
- Time required: 20+ minutes
- Description: Students will experiment and learn about the gear ratios on a bicycle—thus enhancing their understanding of circumference of a circle, proportions, etc. Actual gear ratio would be the ratio between the front and rear sprocket, NOT between pedal and rear wheel.
- Implementation notes (follow up/discussion questions, pedagogical recommendations, etc.): see attachment
- Created by: Karon Klipple, San Diego City College
- Type of activity (hands on activity, lecture, small group problem solving (paper and pencil)
- Course level: Pre Algebra
- Topic(s): ratios and proportions, slope and rate of change, exponents, percents
- Materials: see attached
- Time required: adjustable
- Description: These activities explore population growth rates and its consequences with
regard to the distribution of natural resources. Population growth is perhaps the most important environmental issue of our time.
As population increases and as people seek to raise their standard of living, more stress is put on our earth’s finite resources.One aspect of the population issue is the sheer magnitude of the numbers involved. World population did not reach 1 billion until the year 1800. Since then it has grown exponentially to reach our current 6.7 billion. - Implementation notes (follow up/discussion questions, pedagogical recommendations, etc.): see attachments
- Created by: Alan Bass, San Diego Mesa College
- Type of activity: hands on activity
- Course level: Pre Algebra
- Topic: Proportions
- Materials: Metric measuring tools, cm square tiles or cm square graph paper, scientific calculator
- Time required: 45 minutes
- Description: Students will investigate the use of linear scaling to enlarge or shrink a variety of objects.
- By having the students do the activity in class they can ‘see’ that scaling in one direction may cause the other to over flow the allowable dimension or under fill it.
- Ensure that the students realize that if they scale an object in one direction by a given amount; they must scale the same amount in the other direction.
- Question #3 should be done at home.
- Explain how to create a cm. grid over a picture.
- Implementation notes (follow up/discussion questions, pedagogical recommendations, etc.): Have students research the size of the Statue of Liberty to see how close their answers are to the actual size.
- Created by: Your name, San Diego City College
- Type of activity: small group problem solving (paper and pencil)
- Course level: Pre Algebra
- Topic: Rates
- Materials: The data for this lab will be collected outside of class. Each group will need at least one person that has a vehicle or can get the required information about a vehicle:
- Vehicle will need to be filled with gas (to the first “click” of the pump)
- Record the number of gallons it took to fill up the vehicle
- Record the number of miles on the vehicle at the time of fill up (This will need to be done at least twice in a row with the same vehicle.)
- Time required:35 minutes over two different class periods (see attachment for additional details)
- Description: The purpose of this lab is to calculate the MPG (Miles Per Gallon) of a vehicle, and then use this to approximate the cost of driving the vehicle for a year. Each group should identify the vehicles (hopefully, more than one per group) that will be used, and make a plan to have the required data and results before the second session so that they will be prepared to present their results to the class (this plan may be made as a preliminary assignment).
- Implementation notes (follow up/discussion questions, pedagogical recommendations, etc.): Encourage students to compare (in their results) possible money saving options (buying a new or used car with more fuel efficiency, taking the bus, etc.). Also, if there is enough time between Period One and Period Two listed above, students could compare the mileage at two different octanes of gasoline, and find the “dollars per mile” (or “miles per dollar”) cost of driving (with current gas prices). (see attachment for additional details)
- Created by: Karon Klipple, San Diego City College
- Type of activity: lecture, small group problem solving (paper and pencil)
- Course level: Pre Algebra
- Topic: Ratios
- Materials: none
- Time required
- Description: Students will explore ratios by calculating and comparing/contrasting the ratio of consumption of fossil fuels to production of fossil fuels for the United States, Africa and the Middle East.
- Implementation notes (follow up/discussion questions, pedagogical recommendations, etc.): See instructor document below
