Teaching for Understanding Division with Fractions Dr. DeAnn Huinker, Dr. Kevin McLeod, Dr. Henry Kepner University of Wisconsin- Milwaukee Math Teacher Leader (MTL) Seminar Milwaukee Public Schools June 2005 This material is based upon work supported by the National Science Foundation Grant No. EHR-0314898.
33
Embed
Teaching for Understanding Division with Fractions Dr. DeAnn Huinker, Dr. Kevin McLeod, Dr. Henry Kepner University of Wisconsin-Milwaukee Math Teacher.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Teaching for UnderstandingDivision with Fractions
Dr. DeAnn Huinker, Dr. Kevin McLeod, Dr. Henry Kepner University of Wisconsin-Milwaukee
Math Teacher Leader (MTL) SeminarMilwaukee Public Schools
June 2005This material is based upon work supported by the National Science Foundation Grant No. EHR-0314898.
Session Goals
Deepen conceptual understanding of division with fractions.
Examine “why” we can invert and multiply.
Popcorn PartyServing Size: 2 cups
How many servings from:
8 cups of popcorn
5 cups of popcorn
Summarize
Write the equation for each situation (8 cups; 5 cups).
Identify the meaning of each number in the equations.
SummarizeHow many 2–cup servings?
8 ÷ 2 = 4 cups cup servings
serving
5 ÷ 2 = 2 cups cup
serving
12
servings
What does the represent?
One-half of a cup of popcorn?
One-half of a serving?
Are you sure?
12
Popcorn PartyServing Size: cup
How many servings from:
1 cup of popcorn
4 cups
2 cups
12
12
SummarizeHow many 2–cup servings?
1 ÷ = 2 cup servings
4 ÷ = 8 cups servings
12
cupservin
g12
cupservin
g
TaskPopcorn Parties #1 & #2
Facilitator
Paper Strip Demonstrator
Algorithm
TaskPopcorn Parties #1 & #2
Facilitator poses one problem at a time.
Each individual silently solves it.
On facilitator’s cue: State answer.
Demonstrator models with paper strips.
Take turns to justify your reasoning.
Popcorn Party #1
Serving Size: cup of popcorn
How many servings can be made from: 1 cup of popcorn 2 cups of popcorn 3 1/2 cups of popcorn
14
Popcorn Party #2
Serving Size: cup of popcorn
How many servings can be made from: 3/4 cup of popcorn 6 cups of popcorn 2 1/4 cups of popcorn 4 1/2 cups of popcorn
34
Popcorn PartyServing Size: cup
How many servings from 4 cups?
34
SummarizeHow many 2–cup servings?
4 ÷ = cups
34
cupservin
g
Discussion
In reviewing these division situations and
your solutions, what are you noticing?
Fraction Division Algorithm Photo Sequence from Session
7 X = 1?
a X = 1?
Multiply by the inverse, which is also called the reciprocal.