Life's percents
Students will gather data from their own lives to use in calculating percents. They will measure parts of their bodies (head, leg, neck, etc.), complete a class survey that asks information about themselves, and use a pay stub to find percentages of deductions.
A lesson plan for grades 6–7 Mathematics
Learning outcomes
Students will
- calculate percentages given various types of data.
- organize data into a chart for easier use.
- compare data through the use of percentages.
Teacher planning
Time required for lesson
90 minutes
Materials/resources
- paper & pencil
- tape measure
- pay stub
- percent graphic
- calculators (This would be a good time to introduce graphing calculators, but it is not required.)
Pre-activities
Students should be able to solve equations using multiplication and division.
Activities
Activity I
- Ask the students to estimate what percentage of their height is their head? torso? leg? neck? You might need to emphasize that you are referring to the body as a “whole” 100%.
- Students will measure height of each body part (i.e. head, torso, leg). They will also measure their entire body for their complete height. It is best to pair students by sex so as to avoid possible misconduct. Instruct students to measure in inches. If they know their height then that is a good opportunity to demonstrate how to convert feet to inches - a “teachable moment.” Students should record the data in chart form. Demonstrate the chart on an overhead or on the board.
- After measurements have been completed, have students return to their seats. Introduce to students how to calculate percents. Word choice is important. Have students place the part as the numerator and the whole height as the denominator. Explain how to represent percentages by either moving the decimal two spaces to the right or by multiplying by 100. Students will complete their charts by calculating the percentages.
Activity II
- Ask the class, “Who owns a dog?” On the board write the header dog and place tally marks for each person that raises their hand. Prompt the students to give you a variety of topics. Some suggestions are siblings, taller than 6ft, like to swim, watch soap operas, etc. Give the students a chance to come to the board and place a tally mark for each header that applies to them. Groups of 5-7 work fairly well.
- After students have completed this survey, ask students to find the percentage of people in class for each header. Give the students a chance to realize they need to count how many people are in the class to get the whole amount. Have volunteers come to the board and label the percentage for each header.
- When all of the above has taken place, ask the class some clarifying questions. For example, “What percent of students do not like to watch soap operas?” This gives the students a chance to see a different perspective.
Activity III
This activity is a graphic to help students remember how to set up a percent problem. The percent graphic will set up the problem. If you know the percent and the whole amount then you will multiply to get the part. If you know the part and the whole then you will divide to get the percent. Lastly, if you know the part and the percent then you will divide to get the whole.
Activity IV
This last activity leads into the assessment. Show an overhead of apay stub. Talk with students about deductions, gross pay, and net pay, especially as related to percent.
Assessment
Given a pay stub, students will calculate the percentage for each deduction. During the assessment, you will need to monitor students. The expectation is that they will participate and stay on task. I have my students keep a notebook, and the results of the activities should be included. Then as part of my class I give notebook quizzes. Questions about the activities would be included at that time.
Supplemental information
Comments
The personal touch helps motivate the students. You can do all of these activities in one day or you can break it up over a couple of days. I find the students enjoy these activities.
North Carolina Curriculum Alignment
Mathematics (2004)
Grade 6
- Goal 1: Number and Operations - The learner will understand and compute with rational numbers.
- Objective 1.02: Develop meaning for percents.
- Connect the model, number word, and number using a variety of representations.
- Make estimates in appropriate situations.
- Objective 1.02: Develop meaning for percents.
- Goal 5: Algebra - The learner will demonstrate an understanding of simple algebraic expressions.
- Objective 5.04: Use graphs, tables, and symbols to model and solve problems involving rates of change and ratios.
Grade 7
- Goal 1: Number and Operations - The learner will understand and compute with rational numbers.
- Objective 1.01: Develop and use ratios, proportions, and percents to solve problems.
- Goal 5: Algebra - The learner will demonstrate an understanding of linear relations and fundamental algebraic concepts.
- Objective 5.04: Develop fluency in the use of formulas to solve problems.



