Crossing the River with Dogs

transcript

Crossing the River with Dogswith Pete AndersonGlen Allen High SchoolHenrico County

Problem

Learning

Completing Exercises vs Solving Problems

What is Problem Solving?

"A good problem is something you don't know how to solve. That's what makes it a good puzzle and a good opportunity. A good problem does not just sit there in isolation, but serves as a springboard to other interesting questions."

- Paul Lockhart, A Mathematicians Lament

Who’s Responsible for What?

Unit Assessment

Objectives of this Session

0Solve Problems0List Problem Solving Skills0View Resources0View Sample Lesson Plans

Let’s Solve a Problem

Crossing the River ...

0Level 1 – with a wolf, goat, cat, and cabbage

0Level 2 – with Missionaries and Cannibals

0Level 3 – with Dogs

In groups of ___, you have __ minutes to solve the problem.

Level 1: Wolf, Goat, Cat and Cabbage

0Sailor Cat needs to bring a wolf, a goat, and a cabbage across the river. The boat is tiny and can only carry one passenger at a time. If he leaves the wolf and the goat alone together, the wolf will eat the goat. If he leaves the goat and the cabbage alone together, the goat will eat the cabbage. How can he bring all three safely across the river?

0Online version0Flipchart

Level 2: Missionaries and Cannibals

0Three missionaries and three cannibals must cross a river using a boat which can carry at most two people, under the constraint that, for both banks, if there are missionaries present on the bank, they cannot be outnumbered by cannibals (if they were, the cannibals would eat the missionaries.) The boat cannot cross the river by itself with no people on board. How can they all cross the river alive?

0Online version0Flipchart

Level 3: Crossing the River with Dogs

0 The situation: The five members of a family and their five dogs (each family member owned one of the dogs) were hiking when they encountered a river to cross. They rented a boat that could hold three living things: people or dogs. Unfortunately, the dogs were temperamental. Each was comfortable only with its owner and could not be near another person, not even momentarily, unless its owner was present. The dogs could be with other dogs, however, without their owners. The crossing would have been impossible except that Lisa’s dog had attended a first-rate obedience school and knew how to operate the boat. No other dogs were that well educated.

0 The task: Explain in detail how do the five family members and their dogs cross the river?

How did you solve the problem?

0What skills were required?0What previous knowledge was required?0 Is there more than one solution? Is one solution better

than another?

The Locker Problem

Rubrics Drive Instruction

My 1st Quiz

Problem Solving Skills

0Draw a Diagram0Systematic Lists0Eliminate Possibilities0Matrix Logic0Look for a Pattern0Guess and Check0Sub-problems0Unit Analysis

Problem Solving Skills

0Solve an Easier Related Problem0Physical Representations0Work Backwards0Venn Diagrams0Algebra0Finite Differences0Other Ways to Organize Information0Other Ways to Change Focus0Other Forms of Spatial Organization

A text by Ted Herr and Ken Johnson

0Problem Solving Strategies: Crossing the River With Dogs and Other Mathematical Adventures(ISBN: 1559530685 / 1-55953-068-5 )

0Available at AbeBooks.com for as little as $1 (used).

0GAHS Math text samples

Reading and Writing Across the Curriculum

Is this worth teaching?

TIPC Chart

Integrating Mathematics What are the rules?

0Level 1: Coordinates of a Point0Level 2: Equation of a Line0Level 3: Equation of a Quadratic

0Free web based “software”. 0No download necessary.0Geogebra.org ( )

Context of each sample: Why are we learning this?

0Level 1: Coordinates of a Point0 Flat Map verse GPS coordinate system

0Level 2: Equation of a Line0 Business Models

0Level 3: Equation of a Quadratic0 Trajectory motion of a ...0 [basketball, model rocket, arrow, etc.]

Sample Lesson Plans

0Option #1 – Traditional + Technology0Option #2 – Problem Based Learning 0Option #3 – PBL + Lecture0Option #4 – Vodcast Enhanced

My County’s Pacing Guide

My Pacing Guide 2010-2011

Lesson 1-1: Point, Line, Plane0Standard: none0Objective:

0 The student will be able to make and describe fundamental sketches. The student will also be able to understand basic concepts such as intersect, horizontal, vertical, collinear and coplanar.

0Essential Questions:0 How does a system of rules help us create sketches from

verbal descriptions and vice versa? 0 What is the vocabulary of Geometry in terms of nouns, verbs,

and adjectives?

PBL Lesson Plan 1-10 Setting: small group (2-5)0 Activity Directions:

1. One student (team leader) will have the picture to describe. All other group members will have one sheet of blank paper.

2. The team leader must describe the picture verbally while the rest of the group, while working together, attempts to draw the picture. The team leader may only use words. This team will have no more than two minutes to create the sketch.

3. Each team has a different picture and exchange pictures (rotate to another team) until each group has tried every picture.

4. Team sketches will be shared with the whole class (show and tell)5. Each team will be assigned one picture and must describe it in a tweet.

0 Picture Sources: Not so well know paintings by famous artists such as Monet, Van Gogh, etc..

[the whole plan]

Lesson 1-2: Segments and Rays0Standard: none0Objective:

0 The student will be able to define segment, ray, opposite rays, congruent, midpoint, bisect, length and postulate. The "Ruler Postulate" and "Segment Addition Postulate" will be introduced.

0Essential Question:0 What is the difference between equality and congruence?

PBL Lesson Plan 1-20 Setting: small group (2-5)0 Activity Directions:

1. Each student in the group has a piece of paper, metric ruler, and pencil.2. Each group is assigned a length (in millimeters). This length is to be kept secret from

the other groups in the classroom. 3. Each member of the group is to draw a segment exactly the assigned length.4. Groups exchange/rotate papers to another group. 5. Each group measures the length of the segment and records the length on the paper.

Each member of the group shares their finds on each paper and comes to a consensus of the mystery length.

6. [optional] Exchange papers again to a new group.7. Return papers to the original group.8. Discussion Question: Name two objects that are [exactly] equal?

0 Leading Questions from the Teacher:0 What is “margin of error”?0 If two “pencils” appear to be equal in length, could we not “zoom in” on the ruler and find

that they are ever so slightly different?

[the whole plan]

What are the Good Problems?

blog post

The 4 Ds

Define: Write a list of questions but do not answer them yet. “What do you need to do or know in order to solve this problem?”

Design: Create a working sketch and equation that will solve the problem.

Do: Gather information needed to substitute into the equation and solve.

Debrief: Turn in your work with the grade you believe you have earned. Discuss with the teacher why you deserve this grade.

Always with a Rubric

Crossing the River with Dogswith Pete AndersonGlen Allen High SchoolHenrico County

Problem

Learning

Thank You.

Crossing the River with Dogs

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