Lesson Plan #: AELP-MPS0204


Mind-Bending Math Riddles

An Educator's Reference Desk Lesson Plan


Submitted by: Steven Yanni
Email: smyst3@pitt.edu
School/University/Affiliation: University of Pittsburgh at Johnstown
Endorsed by: Professor Bernard J. Poole
             University of Pittsburgh at Johnstown

Date: September 18, 2002


Grade Level: 5, 6

Subject(s):

Duration: 45 minutes

Description: The lesson plan centers on Tang's selection of children's literature, The Grapes of Math . The riddles within the book are meant to stretch students' thinking skills and to force them to find efficient ways to solve mathematical problems.

Goals: Pennsylvania Academic Standards for Mathematics :

Objectives:
  1. Students will be able to work cooperatively in teams of four or five to develop strategies for solving the "mind-bending" riddles.
  2. Students will be able to address their peers in other groups to share their strategies for solving the riddles.
  3. Students will be able to provide feedback to their peers about the strengths and weaknesses of the strategies.
  4. Students will be able to create a picture and devise a strategy to solve a problem similar to the riddles solved in the main part of the lesson.
Materials:

Vocabulary:

  1. riddle - puzzling question posed as a problem to be solved
  2. pattern - repeated characteristic in an object
  3. strategy - the art of devising or employing plans or stratagems toward a goal
  4. reason - to justify or support
Procedure:

[ Author's Note: In his book, Greg Tang presents a myriad of mathematical riddles to be solved by student mathematicians. Tang presents 16 riddles, each accompanied by a beautifully colored picture that depicts a visual clue to the reader. Harry Briggs, the illustrator of Tang’s The Grapes of Math , relates the riddles to real life by depicting pictures of dice, ants, camels, fish, fruit, and so on. Tang provides a hint for every riddle. With the hints, the book could be used in the lower grades; without the hints, as is in my lesson, the riddles can be used with students in the intermediate grades. The riddles are fun and well-planned.]

Begin the lesson by telling the students that they will be working on riddles and creating problem-solving strategies to solve the riddles. Ask for volunteers to tell a riddle to the class (in a perfect world, the riddle will have some relation to mathematics). As a class, solve the riddle. Present the following words to the students: riddle, pattern, strategy, and reason. Tap the students' knowledge about the words to see what they already know about the terms. Define the words (the teacher can use an overhead projector or a PowerPoint presentation).

Present the first riddle (minus the hint) in the book (via PowerPoint or the overhead projector). Show the students that counting each object on the page takes far too long and is not efficient. Devise an efficient strategy to solve the riddle. In the case of this riddle, "Fish School," show the students that they have to look askew (i.e. count the fish in the first diagonal, (4), and count how many rows (4); thus, there are 16 fish). Model a problem-solving strategy used to solve the riddle, "Fish School." Divide the students into cooperative teams of four or five students. Give each team 3 riddles to solve. Be sure to tell them that they are not to count each object individually on the page; rather, they should devise a more efficient strategy to solve each riddle. Students will have 15-20 minutes to complete the task.

As students work in their cooperative teams, circulate around the room providing feedback and reinforcement as needed. Be careful to praise all students to foster an enjoyment of the activity. After 15 or 20 minutes of work has passed, assemble the students in a circle on the floor around the blackboard and the overhead projector. Show the students each riddle via a transparency (hint omitted). Ask for a volunteer from each group to stand up in front of the class and communicate to the groups the strategies that they used to solve each riddle. Allow for feedback from all students. Perhaps students from another group may find an equally valid way to solve the problem. (Be careful with praise and do not merely correct answers; explain how the answers could be tailored to make them correct). After all groups have completed the riddles and have shown the class how to solve each one, the groups should return to their desks to create their own riddles. Their riddles should include a hint on how to solve the problem. Although the riddles in the text may be used as a guide, the riddle may NOT be an exact replica of one in the text. The class will end with the discussion of each riddle. Each group will present its riddle, and students' work will be hung on the class bulletin board for all to see.

Assessment: Note how the students worked cooperatively in teams to solve the riddles. Note how the students addressed their peers to share their strategies for solving the riddles. Note the students' accuracy in providing feedback to their peers about the strengths and weaknesses of the strategies used. Observe students' abilities to create a picture and devise a strategy to solve a riddle on their own.

Useful Internet Resource:
* Pennsylvania Academic Standards for Mathematics
http://www.pde.state.pa.us/k12/lib/k12/MATH.pdf

Special Comments:

Special Needs Adaptations:

Technology Integration: