This activity has students conduct a sample survey of how many left-handed people there are in your school.
Additional Resources
About Teaching Mathematics: A K-8 Resource, 2nd Edition by Marilyn Burns
By taking a sample of some people in your school, can you determine approximately how many right-handed people there are for every lefthanded person? This experiment has students conduct a sample survey of how many left-handed people there are in your school. Students then conduct a school-wide survey and compare the results of the two surveys.
1. Demonstrate a positive learning attitude toward mathematics.
4. Communicate mathematically.
Invitation to Learn
When students enter the room, have a piece of paper on each student's
desk. Any paper will do; used or scratch. Ask students to hold their paper in
their hand and do what you do to your paper. Wad up your paper into a ball,
tight enough to throw the paper. Then have students stand up, and throw their
paper toward the front of the classroom, and try to "hit" the chalkboard/whiteboard.
Then have students sit down.
Instructional Procedures
Begin a discussion about throwing. Ask which students used their left hand to
throw the paper towards the front of the classroom and which students used their
right hands. Discuss how many students write with their left or right hands.
Determine as a class how many left-handed and how many right-handed people are
in your class. This may need to be clarified by what you use to determine if
you are left or right-handed (throwing, writing, eating, etc.). Write the different
ways of expressing the results of the class survey. For example: We have 18
right-handed students and 7 left-handed students; 18/25 of the class are right-handed,
7/25 are right-handed; 18 out of 25 students are right-handed and 7 out of 25
are left-handed; we have a ratio of 18:25 right-handed students and 7:25 left-handed
students.
Pose a part of the problem:
Tell students you would like to find a way to count the number of people in
your school. Ask: How could we find out how many people are in our school? Discuss
if you will be counting ALL people, including teachers and staff, or just the
students. After you have decided which people you will count for your experiment,
tell students you are going to try to find out how many left-handed people there
are for every right-handed person. You will then compare the results of your
class survey with the results of the school census.
When all people in the school have been surveyed, compile your results. How many right handed people are there for each left-handed person in the entire school? Are the results similar to that of your class survey? Were you satisfied with your sampling procedure (taking a class sample)? If not, how would you improve the way you sampled?
Curriculum Integration
Math/Science--Discuss with students if left-handed vs. right-handed is
an inherited trait. Connect this to their study of inherited traits in Science.
Possible Extensions/Adaptation
This procedure can be used by individuals or small groups of students to investigate
a variety of topics:
By sampling, determine approximately how many red-, blond-, brown-, and black-haired people there are in your school.
By sampling, decide how many people there are with each eye color.
Use sampling to determine the favorite TV show of students in your school.
Homework & Family Connections
A possible homework/extension to this activity would be for students to take
a survey of at least 10 people from home, their neighborhood, on their bus,
etc., to compare with the school wide survey taken.
Students should report their homework results to class the next day. Total the number of left-handed vs. right-handed people outside of the school. Compare these results with the results of the classroom survey and the school wide survey.
Students will write a report about their right-handed vs. left-handed experiment. Ask students to be sure to include numbers and comparisons in their written report. Students can share their written reports in small groups or with the entire class. You may want students to revise their reports, clarify any unclear details and even illustrating their findings in the form of a graph. Provide graph paper, chart paper, crayons, markers, etc. These can be posted in the classroom or on a favorite bulletin board for all to see.