1 lessons learned from our research in ontario classrooms
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Lessons Learned from Our Research in Ontario Classrooms
Shelley YearlyCathy Bruce
3 out of 2 people have trouble with fractions….
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[email protected]@trentu.ca
www.tmerc.ca
Why Fractions?• Students have intuitive and early understandings of ½
(Gould, 2006), 100%, 50% (Moss & Case, 1999)
• Teachers and researchers have typically described fractions learning as a challenging area of the mathematics curriculum (e.g., Gould, Outhred, & Mitchelmore, 2006; Hiebert 1988; NAEP, 2005).
• The understanding of part/whole relationships, procedural complexity, and challenging notation, have all been connected to why fractions are considered an area of such difficulty. (Bruce & Ross, 2009)
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Why Fractions?• Students also seem to have difficulty retaining fractions concepts (Groff,
1996).
• Adults continue to struggle with fractions concepts (Lipkus, Samsa, & Rimer, 2001; Reyna & Brainerd, 2007) even when fractions are important to daily work related tasks.
• “Pediatricians, nurses, and pharmacists…were tested for errors resulting from the calculation of drug doses for neonatal intensive care infants… Of the calculation errors identified, 38.5% of pediatricians' errors, 56% of nurses' errors, and 1% of pharmacists' errors would have resulted in administration of 10 times the prescribed dose." (Grillo, Latif, & Stolte, 2001, p.168).
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We grew interested in…
• What types of representations of fractions are students relying on?
• And which representations are most effective in which contexts?
• We used Collaborative Action Research to learn more
Data Collection and Analysis
AS A STARTING POINT
•Literature review•Diagnostic student assessment (pre)•Preliminary exploratory lessons (with video for further analysis)
Data Collection and AnalysisTHROUGHOUT THE PROCESS
•Gathered and analysed student work samples•Documented all team meetings with field notes and video (transcripts and analysis of video excerpts)•Co-planned and co-taught exploratory lessons (with video for further analysis after debriefs)•Cross-group sharing of artifacts
Data Collection and Analysis
TOWARD THE END OF THE PROCESS
•Gathered and analysed student work samples •Focus group interviews with team members•30 extended task-based student interviews•Post assessments
Your Turn: “Matching Game”
TWO FIFTHS OF THE PETALS ARE WHITE
Match again: “Triplets”
• Part-whole relationship• Part-part relationship• Linear relationship• Quotient relationship• Operator relationship
• Do your third match, and discuss
In our study…
• We focused particularly on these three
Tad Watanabe, 2002
Early Findings• Students had a fragile and sometimes conflicting
understanding of fraction concepts when we let them talk and explore without immediate correction
• Probing student thinking uncovered some misconceptions, even when their written work appeared correct
• ‘Simple’ tasks required complex mathematical thinking and proving
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Represent 2/5 or 4/10
Early ratio thinking?
Multiple Meanings Simultaneously
Fraction Situations
Lucy walks 1 1/2 km to school. Bella walks 1 3/8 km to school. Who walks farther? What picture would help represent this fraction story?
Circles are just easier
But it simply isn’t true…
1. They don’t fit all situations
2. They are hard to partition equally (other than halves and quarters)
3. It can be hard to compare fractional amounts.
Typical Partitioning Challenges
Show video of kid trying to partition a circle to show 2/5ths• <<Shelley to locate/add>>
Over-reliance on circles to compare fractions can lead to errors and misconceptions…
No matter what the situation, students defaulted to pizzas or pies…
We had to teach another method for comparing fractions to move them forward…
Beyond Counting• Using pre-partitioned shapes in teaching and
assessing can mask an incomplete or incorrect appreciation of fractions as relational numbers.
• Students are adopting only part of a regional “part of a whole” model of fractions. That is, some students focus on the “number of pieces” named by a fraction and others the “number of equal pieces” named, without addressing the relationship between the area of the parts compared to the area of the whole region.
Gould, Outhred, Mitchelmore
Number Lines
So we looked closely at linear models…
How do students: -think about numbers between 0 and 1-partition using the number line-understand equivalent fractions and how to place them on the number line
Why Number Lines?Lewis (p.43) states that placing fractions on a number line is crucial to student understanding. It allows them to:
•Further develop their understanding of fraction size•See that the interval between two fractions can be further partitioned•See that the same point on the number line represents an infinite number of equivalent fractions
Fractions on Stacked Number Lines
Exploratory Lesson: Ordering Fractions on a Number Line• supports student acquisition of an understanding
of the relative quantity of fractions (beyond procedural)
• allows students to understand density of fractions
• reinforces the concept of the whole
Your Turn: “Number line 0-4”
• ½ • 100%• 7/18• 2 5/6• 0.99• Sticky arrows with fractions, percents and
decimals
Exploratory Lesson Video
• Shelley look for number line video
Other Challenges & Misconceptions Encountered
Some Common Misconceptions Translates to…
Area Models: Size of the partitioned areas doesn’t matter when using an area model, just the number of pieces
Approximations in drawings (is it good enough? Understanding the need for equal parts, but approximating equal parts in area model drawings)
Set Models: Fractions cannot represent ‘parts of a set’. All representations of fractions must show the ‘parts’ as attached or touching, and all parts must be exactly the same no matter how the set might be named
Inability to see the following as a fraction relationship:
Equivalent Fractions: Always involve doubling
1/2 then 2/4 then 4/8 then 8/16(5/10ths would not be considered in this scenario)
The numerator and denominator in a fraction are not deeply related: (that the fraction has two numbers that represent a value because the numbers have a relationship)
2/5ths is equal to 1/10th because 2 fives are 10 and 1 ten is 10Note - Use of fraction language by educators may contribute to this problem: When we show a fraction, but don’t say it, the students seem to have multiple ways of naming it themselves, some of which are confusing (e.g., one over ten)
Some instructional moves Included:• having students compose and decompose
fractions with and without concrete materials• revisiting the same concept in a number of
different contexts• exploring how different representations were
more appropriate to some contexts
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Implications for Teaching
• Expose students to precise representations in precise contexts
• Get students to connect representations with stories in context to make better decisions about which representation(s) to use when
• Lots of exposure to representations other than part-whole relationships (discreet relationship models are important as well as continuous relationship models, as early as possible)
Implications for Teaching
• Discussion/class math-talk to enhance the language of fractions
• Use visual representations as the site for the problem solving (increased flexibility)
• Think more about how to teach equivalent fractions
• Think more about the use of the number line
Which Representation When?Number Lines•Fraction as number•Density of fractions•Comparing •Ordering•Operations (+, -, x, /)
Circle Area Modelswith circle friendly fractions, such as ½, ¼, 1/8, 1/3
•Comparing•Ordering •Operations (+, -, x, /)
Rectangle Area Models•Using factors to generate equivalent fractions•Comparing•Ordering •Operations (+, -, x, /)
Teacher Learning• Let’s hear the debrief after the lesson.
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Knowledge Creation: CAR
• Build knowledge at CAMPPP just like teachers learning together in classroom contexts and with one another