Understanding Fraction Representations

Session 3

Amy LeHewElementary Math Facilitator Meeting

November 2012

What is the MOST EFFECTIVE way to

- Introduce fractions on a number line?- Build understanding of fractions as a

number on a number line?

Agenda

Draw a number line from 0 to 5

Place the number ¾ on your number line.

How do you think your 3rd, 4th, 5th graders would solve this?

Math Task

Asked 3rd- 4th -5th grade students to write 7/8 on a number line from 0-8.

Guess where they put it?

Why would they place 7/8 between 7 and 8?

California Mathematics Project Task Force

Take a look at the student samples at your table.

What evidence do you see of Misconceptions Understandings?

I wonder what would happen in CMS…

Here’s What they Said

“You can’t have the number line without fractions; you

can’t have fractions without a number line. Number lines are not optional.”

Phil Daro, January 2011

Wu asserted that ‘The number line is to fractions what one’s fingers are to whole numbers…’”

We have 10 additional days added to Unit 7

You’ve been collaborating with peers around fraction representations, the Common Core, and Number Lines

I am not writing these lessons… WE ARE

Enough Talking!

How is a unit written anyway?

Review Unit 7 for 3rd grade to get a sense of

- the work students will do- the standards addressed

-connections that could be made to number lines.

In Georgia Measurement unit, students had 1 experience collecting shoe size and measuring shoe length with cubes (just to get them thinking

about measurement and data).

Goal: by the end of the 2 weeks students will own the number line and see fractions as numbers on number lines.

Your plan must include lessons for…- Folding (partitioning lengths)- Measuring and plotting lengths to nearest half

and quarter inch- Finding equivalent fractions on a number line- *Have NF standards and MD.4 standard

written all over them!

Create a 10-Day Plan

Your plan must include lessons for…- Folding (partitioning lengths)- Measuring and plotting lengths to nearest half and quarter inch- Finding equivalent fractions on a number line

Create a 10-Day PlanResources around the

Room:

- Reading materials- Assessment items- Activities- Lessons- Student Work

Be thoughtfulBe critical

Develop understanding of fractions as numbers.1. Understand a fraction 1/b as the quantity formed by 1 part when a whole is partitioned into b equal parts; understand a

fraction a/b as the quantity formed by a parts of size 1/b. 2. Understand a fraction as a number on the number line; represent fractions on a number line diagram. Represent a fraction 1/b on a number line diagram by defining the interval from 0 to 1 as the whole and partitioning it into b equal

parts. Recognize that each part has size 1/b and that the endpoint of the part based at 0 locates the number 1/b on the number line.

Represent a fraction a/b on a number line diagram by marking off a lengths 1/b from 0. Recognize that the resulting interval has size a/b and that its endpoint locates the number a/b on the number line.

3. Explain equivalence of fractions in special cases, and compare fractions by reasoning about their size. a. Understand two fractions as equivalent (equal) if they are the same size, or the same point on a number line. b. Recognize and generate simple equivalent fractions, e.g., 1/2 = 2/4, 4/6 = 2/3). Explain why the fractions are equivalent, e.g., by using a visual fraction model. c. Express whole numbers as fractions, and recognize fractions that are equivalent to whole numbers. Examples: Express 3 in the form 3 = 3/1; recognize that 6/1 = 6; locate 4/4 and 1 at the same point of a number line diagram. d. Compare two fractions with the same numerator or the same denominator by reasoning about their size. Recognize that comparisons are valid only when the two fractions refer to the same whole. Record the results of comparisons with the symbols >, =, or <, and justify the conclusions, e.g., by using a visual fraction model.

3.MD.4. Generate measurement data by measuring lengths using rulers marked with halves and fourths of an inch. Show the data by making a line plot, where the horizontal scale is marked off in appropriate units— whole numbers, halves, or quarters.

What questions might we all ask 10 third grade students to get a sense of where they are with number line work?

ASK at least 5 students at your school and bring back video and/or paper evidence!

Homework (actually, schoolwork)