The Nature of Knowledge for 
Teaching and Implications for 
Research and Practice 
Yopp Distinguished Speaker Series 
University of North Carolina, Greensboro 
September 8, 2014 
Dr. Randy Philipp 
San Diego State University 
RPhilipp@mail.sdsu.edu
Thank You! 
UNCG Mathematics Education Group in the 
School of Education 
The Graduate Students 
James D. and Johanna F. Yopp
Presentation Plan 
• Knowledge for Teaching and Knowledge 
for Teaching a Particular Subject 
• Assessing Specialized Content Knowledge 
• Rethinking Specialized Content Knowledge 
in a Particular Domain 
• Discussion
Presentation Plan 
• Knowledge for Teaching and Knowledge 
for Teaching a Particular Subject 
• Assessing Specialized Content Knowledge 
• Rethinking Specialized Content Knowledge 
in a Particular Domain 
• Discussion
What Knowledge of Mathematics Do 
Teachers Need? 
Example, Javier, Grade 5 
At the time of this 
interview, Javier had 
been in the United 
States about one year, 
and he did not speak 
English before coming 
to this country. 
(Javier, VC #6, 0:00 - 1:10)
One Representation of Javier’s Thinking 
6 × 12 
= (5 × 12) + (1 × 12) 
= [(1 
2 
× 10) × 12] + 12 
= [1 
2 
× (10 × 12)] + 12 
= [1 
2 
× (120)] + 12 
= 60 + 12 
= 72
One Representation of Javier’s Thinking 
6 × 12 
= (5 × 12) + (1 × 12) (Distributive prop. of x over +) 
= [(1 
2 
× 10) × 12] + 12 (Substitution property) 
= [1 
2 
× (10 × 12)] + 12 (Associative property of x) 
= [1 
2 
× (120)] + 12 
= 60 + 12 
= 72
One Representation of Javier’s Thinking 
6 × 12 
= (5 × 12) + (1 × 12) (Distributive prop. of x over +) 
= [(1 
2 
× 10) × 12] + 12 (Substitution property) 
= [1 
2 
× (10 × 12)] + 12 (Associative property of x) 
= [1 
2 
× (120)] + 12 
= 60 + 12 
= 72 
Place value
Unpacking The Knowledge Demands 
What is the nature/category/classification of the 
knowledge required to… 
…solve 12 x 6 procedurally? 
…solve 12 x 6 using number sense? 
…understand Javier’s (and other students’) reasoning? 
…think to ask “How did you know that 12 x 5 is 60?” 
…think of a productive follow-up question to pose to 
Javier after he solved this task? 
…situate the mathematical issues embedded in Javier’s 
thinking in terms of the mathematics that has come 
before and how these ideas might unfold in future 
mathematics courses?
Knowledge 
for 
Teaching 
Ball, 
Hill, 
& 
Bass, 
2005; 
Hill, 
Sleep, 
Lewis, 
& 
Ball, 
2007 
Common 
Content 
Knowledge—the 
knowledge 
teachers 
are 
responsible 
for 
developing 
in 
students 
Evaluate 
and 
understand 
the 
meaning 
of 
12 
÷ 
3. 
Specialized 
Content 
Knowledge—knowledge 
that 
is 
used 
in 
teaching, 
but 
not 
directly 
taught 
to 
students 
Write 
a 
real-­‐life 
story 
problem 
that 
could 
be 
represented 
by 
the 
expression 
12 
÷ 
3. 
Pedagogical 
Content 
Knowledge 
(Shulman, 
1986)—the 
ways 
of 
represenCng 
and 
formulaCng 
the 
subject 
that 
make 
it 
comprehensible 
to 
others 
including 
knowledge 
of 
how 
students 
think, 
know, 
and 
learn. 
How 
might 
children 
reason 
about 
this 
task?
Unpacking The Knowledge Demands 
What is the nature/category/ 
classification of the knowledge 
required to… 
…solve 12 x 6 procedurally? 
…solve 12 x 6 using number sense? 
…understand Javier’s (and other 
students’) reasoning? 
…think to ask “How did you know 
that 12 x 5 is 60?” 
CCK 
CCK, SCK 
CCK, SCK, PCK 
CCK, SCK, PCK
Consider an example of SCK in a field 
other than mathematics 
Common 
Content 
Knowledge—the 
knowledge 
teachers 
are 
responsible 
for 
developing 
in 
students 
Specialized 
Content 
Knowledge—knowledge 
that 
is 
used 
in 
teaching, 
but 
not 
directly 
taught 
to 
students 
Pedagogical 
Content 
Knowledge 
(Shulman, 
1986)—the 
ways 
of 
represenCng 
and 
formulaCng 
the 
subject 
that 
make 
it 
comprehensible 
to 
others 
including 
knowledge 
of 
how 
students 
think, 
know, 
and 
learn. 
Is this knowledge taught? If so, where? If not, why not? 
Is this knowledge assessed by researchers? How?
Presentation Plan 
• Knowledge for Teaching and Knowledge 
for Teaching a Particular Subject 
• Assessing Specialized Content Knowledge 
• Rethinking Specialized Content Knowledge 
in a Particular Domain 
• Discussion
Principal Investigators 
Randy Philipp, PI 
Vicki Jacobs, co-PI 
Faculty Associates 
Lisa Lamb, Jessica Pierson 
Research Associate 
Bonnie Schappelle 
Project Coordinators 
Candace Cabral 
Graduate Students 
John (Zig) Siegfried 
Others 
Chris Macias-Papierniak, 
Courtney White 
Funded by the National Science Foundation, ESI-0455785
Participant Groups (N=129 with 30+ per group) 
PSTs, Prospective Teachers 
Undergraduates enrolled in a 
first mathematics-for-teachers content course 
________________________________________________________________________________________________________________________ 
IPs, Initial Participants 
0 years of sustained professional 
development 
APs, Advancing Participants 
2 years of sustained 
professional development 
ETLs, Emerging Teacher Leaders 
At least 4 years of 
sustained professional development and some 
leadership activities 
_______________________________________________ 
SMSs, Strong Mathematics Students - Graduate or 
advanced undergrads taking advanced math courses 
K–3 Teachers
Ones Task 
Andrew Task
Group Means by Task 
(0–4 scale) 
PST IP AP/ETL SMS 
Andrew ? 
Ones ?
Group Means by Task 
(0–4 scale) 
PST IP AP/ETL SMS 
Andrew 1.48 ? 
Ones 1.58 ?
Group Means by Task 
(0–4 scale) 
PST IP AP/ETL SMS 
Andrew ? 1.48 2.36 
Ones ? 1.58 2.49
Group Means by Task 
(0–4 scale) 
PST IP AP/ETL SMS 
Andrew 1.67 1.48 2.36 ? 
Ones 0.31 1.58 2.49
Group Means by Task 
(0–4 scale) 
PST IP AP/ETL SMS 
Andrew 1.67 1.48 2.36 2.55 
Ones 0.31 1.58 2.49
Two ETL’s solution to Andrew Task 
1) Because he made 63 into 65 so that he could solve 
the problem. He got 40 and he subtracted the 2 in 
which he had added to simplify the problem. 
2) 5 = 3 + 2 and if you only have 3 and you're 
subtracting 5, you can take away the 3 but you still have 
two more to take away, hence the -2. 
63 
– 23 
40 
– 2 
38 
63 
- 25 
-2 
40 
38
SMS’s solution to Andrew Task 
Explain why Andrew’s strategy makes mathematical 
sense. 
He makes the problem simpler by subtracting 20 from 60 
and 5 from 3 and adding the results. 
Please solve 432 – 162 = ☐ by applying Andrew’s 
reasoning. 
432 
−162 
0 
− 30 
300 
270 
63 
- 25 
-2 
40 
38
The Land of Specialized Content 
Knowledge 
The$Land$of$Specialized$Content$Knowledge$ 
The$Land$of$SCK$ 
A$Mathema2cal$Path$to$the$ 
Land$of$SCK$ 
A$Path$Through$Children’s$ 
Mathema2cal$Thinking$to$the$ 
Land$of$SCK$
Group Means by Task 
(0–4 scale) 
PST IP AP/ETL SMS 
Andrew 1.67 1.48 2.36 2.55 
Ones 0.31 1.58 2.49 ?
Group Means by Task 
(0–4 scale) 
PST IP AP/ETL SMS 
Andrew 1.67 1.48 2.36 2.55 
Ones 0.31 1.58 2.49 0.94
Presentation Plan 
• Knowledge for Teaching and Knowledge 
for Teaching a Particular Subject 
• Assessing Specialized Content Knowledge 
• Rethinking Specialized Content 
Knowledge in a Particular Domain 
• Discussion
Project Z: Mapping Developmental Trajectories 
of Students’ Conceptions of Integers 
• Lisa Lamb, Jessica Bishop, & Randolph Philipp, Principal 
Investigators 
• Ian Whitacre, Faculty Researcher 
• Spencer Bagley, Casey Hawthorne, Graduate Students 
• Bonnie Schappelle, Mindy Lewis, Candace Cabral, Project 
researchers 
• Kelly Humphrey, Jenn Cumiskey, Danielle Kessler, 
Undergraduate Student Assistants 
Funded by the National Science Foundation, DRL-0918780
Solve each of the following and think about how you 
reasoned. If you have time, solve another way. 
1) 3 – 5 = ___ 
2) -6 – -2 = ___ 
3) - 2 + ___= 4 
4) ___+ -2 = -10
So, Why Negative Numbers? 
Even secondary-school students who can 
successfully operate with negatives have 
trouble explaining. 
KCC Montage, High School, 2:35
So, Why Negative Numbers? 
Many middle-school stud 
ents do not understand 
what they are doing with negatives. 
Valentin, Grade 7, 1:25
So, Why Negative Numbers? 
Many young children hol 
d informal knowledge 
about negatives on which instruction might be 
based. 
Rosie, 1st grade, ___ + 5 = 3, 1:23
One Last Reason… 
• Negative numbers comprise (almost) half of the 
reals!
Why Study Negative Numbers? 
• The literature that exists tends to either point 
out student difficulties, or offer purported 
instructional paths. 
• Too little literature documents students’ 
informal understandings. 
• Can we connect the goals of integer 
instruction to something other than 
procedures? And if so, what might that be?
Ways of Reasoning 
Students who have negative numbers in their 
numeric domains typically approach integer tasks 
using one of the following five ways of reasoning: 
Order-based reasoning 
Analogically based reasoning 
Formal mathematical reasoning 
Computational reasoning
Ways of Reasoning 
Order-based 
Analogically based 
Formal mathematical 
Computational 
RandyLogNec6, Grade 1, 1:11-1:43 
–2 + 5 = __
Ways of Reasoning 
Order-based 
Analogically (Analogy- based) 
Formal mathematical 
Computational 
Roland, Grade 4, 0–0:49 
–5 + –1
Ways of Reasoning 
Order-based 
Analogically based 
Formal mathematical 
Computational 
Roland, Grade 4, 0–0:48, -5 - -3 
-5 – -3
Teachers’ Knowledge About Integers 
To begin to make sense of how teachers think 
about integers, we interviewed 10 seventh-grade 
teachers to determine their 
understanding of integers and their 
perspectives about teaching integers and 
about students’ thinking. We posed integer 
tasks, we asked them about their teaching, 
and we showed them video clips of children 
solving open number sentences.
Research Questions 
1) Do 7th-grade teachers answer integer tasks 
correctly, and if so, how successfully? 
2) Do 7th-grade teachers invoke ways of 
reasoning, or rely instead upon procedures? 
3) Do 7th-grade teachers recognize ways of 
reasoning in students? 
4) How explicitly do 7th-grade teachers 
articulate the kinds of reasoning that they 
use or that students use? 
5) What are the seventh-grade teachers’ goals 
for integer instruction?
Research Questions 
1) Do 7th-grade teachers answer integer tasks 
correctly, and if so, how successfully? 
2) Do 7th-grade teachers invoke ways of 
reasoning, or rely instead upon procedures? 
3) Do 7th-grade teachers recognize ways of 
reasoning in students? 
4) How explicitly do 7th-grade teachers 
articulate the kinds of reasoning that they 
use or that students use? 
5) What are the seventh-grade teachers’ goals 
for integer instruction? 
Yes, very 
successfully.
Research Questions 
1) Do 7th-grade teachers answer integer tasks 
correctly, and if so, how successfully? 
2) Do 7th-grade teachers invoke ways of 
reasoning, or rely instead upon procedures? 
3) Do 7th-grade teachers recognize ways of 
reasoning in students? 
4) How explicitly do 7th-grade teachers 
articulate the kinds of reasoning that they 
use or that students use? 
5) What are the seventh-grade teachers’ goals 
for integer instruction? 
Yes, very 
successfully. 
They invoke ways 
of reasoning.
Research Questions 
1) Do 7th-grade teachers answer integer tasks 
correctly, and if so, how successfully? 
2) Do 7th-grade teachers invoke ways of 
reasoning, or rely instead upon procedures? 
3) Do 7th-grade teachers recognize ways 
of reasoning in students? 
4) How explicitly do 7th-grade teachers 
articulate the kinds of reasoning that they 
use or that students use? 
5) What are the seventh-grade teachers’ goals 
for integer instruction? 
Yes, very 
successfully. 
They invoke ways 
of reasoning. 
This is mixed.
Research Questions 
1) Do 7th-grade teachers answer integer tasks 
correctly, and if so, how successfully? 
2) Do 7th-grade teachers invoke ways of 
reasoning, or rely instead upon procedures? 
3) Do 7th-grade teachers recognize ways of 
reasoning in students? 
4) How explicitly do 7th-grade teachers 
articulate the kinds of reasoning that 
they use or that students use? 
5) What are the seventh-grade teachers’ goals 
for integer instruction? 
Yes, very 
successfully. 
They invoke ways 
of reasoning. 
This is mixed. 
Not at all.
Research Questions 
1) Do 7th-grade teachers answer integer tasks 
correctly, and if so, how successfully? 
2) Do 7th-grade teachers invoke ways of 
reasoning, or rely instead upon procedures? 
3) Do 7th-grade teachers recognize ways of 
reasoning in students? 
4) How explicitly do 7th-grade teachers 
articulate the kinds of reasoning that they 
use or that students use? 
5) What are the seventh-grade teachers’ 
goals for integer instruction? 
Yes, very 
successfully. 
They invoke ways 
of reasoning. 
This is mixed. 
Not at all. 
Almost entirely 
procedural/rule-based.
Brief Examples 
1) Do 7th-grade teachers answer integer tasks 
correctly, and if so, how successfully? 
2) Do 7th-grade teachers invoke ways of 
reasoning, or rely instead upon procedures? 
3) Do 7th-grade teachers recognize ways of 
reasoning in students? 
4) How explicitly do 7th-grade teachers 
articulate the kinds of reasoning that they 
use or that students use? 
5) What are the seventh-grade teachers’ goals 
for integer instruction? 
Yes, very 
successfully. 
They invoke ways 
of reasoning. 
This is mixed. 
Not at all. 
Almost entirely 
procedural/rule-based.
2) Do 7th-grade teachers invoke ways of reasoning, or 
rely instead upon procedures? 
Yes, they do. 
Teachers invoked ways of reasoning. Even with the result 
unknown sentence, -3 + 6 = !, all but one invoked reasoning. 
Example: -3 – ! = 2 
Raymond: “So I am thinking about the number 
line…So I am starting somewhere… and what 
do I do to end up at positive two? I am moving 
one, two, three, four, five––five units to the 
right.” 
“I am moving the opposite direction, so I 
would write down negative five here.” 
Order-based 
reasoning 
Formal 
reasoning
3) Do 7th-grade teachers recognize ways of reasoning 
in students? 
This is mixed. 
Roland, -5 – (-3) 
Jessica: 
“He seems to have a solid understanding 
that adding negatives to negatives gets you 
further away. So in his mind, he is saying, 
so subtracting, that must bring me closer.” 
Raymond: “I think he got confused. There’s no 
context involved…I don’t quite understand 
him when he used the opposite. Opposite of 
what? …He said, “minus minus. I don’t 
believe that he knows the meaning of 
“minus minus.”
Three Implications for Teacher 
Integer Study 
• Revise the Specialized Content Knowledge 
About Integers
Three Implications for Teacher 
Integer Study 
• Revise the Specialized Common Content 
Knowledge About Integers
Three Implications for Teacher 
Integer Study 
• Revise the Specialized Common Content 
Knowledge About Integers 
• Consider the Challenge in Teachers’ 
Adopting New Goals for Integer Instruction
Three Implications for Teacher 
Integer Study 
• Revise the Specialized Common Content 
Knowledge About Integers 
• Consider the Challenge in Teachers’ 
Adopting New Goals for Integer Instruction 
• Stop Seeking the Holy Grail for Integer 
Instruction: There is No One Best 
Approach or Model for Teaching Integers
The relationship among three types of 
knowledge for mathematics teaching.
Thank you. 
Discussion

Philipp am slides

  • 1.
    The Nature ofKnowledge for Teaching and Implications for Research and Practice Yopp Distinguished Speaker Series University of North Carolina, Greensboro September 8, 2014 Dr. Randy Philipp San Diego State University RPhilipp@mail.sdsu.edu
  • 2.
    Thank You! UNCGMathematics Education Group in the School of Education The Graduate Students James D. and Johanna F. Yopp
  • 3.
    Presentation Plan •Knowledge for Teaching and Knowledge for Teaching a Particular Subject • Assessing Specialized Content Knowledge • Rethinking Specialized Content Knowledge in a Particular Domain • Discussion
  • 4.
    Presentation Plan •Knowledge for Teaching and Knowledge for Teaching a Particular Subject • Assessing Specialized Content Knowledge • Rethinking Specialized Content Knowledge in a Particular Domain • Discussion
  • 5.
    What Knowledge ofMathematics Do Teachers Need? Example, Javier, Grade 5 At the time of this interview, Javier had been in the United States about one year, and he did not speak English before coming to this country. (Javier, VC #6, 0:00 - 1:10)
  • 6.
    One Representation ofJavier’s Thinking 6 × 12 = (5 × 12) + (1 × 12) = [(1 2 × 10) × 12] + 12 = [1 2 × (10 × 12)] + 12 = [1 2 × (120)] + 12 = 60 + 12 = 72
  • 7.
    One Representation ofJavier’s Thinking 6 × 12 = (5 × 12) + (1 × 12) (Distributive prop. of x over +) = [(1 2 × 10) × 12] + 12 (Substitution property) = [1 2 × (10 × 12)] + 12 (Associative property of x) = [1 2 × (120)] + 12 = 60 + 12 = 72
  • 8.
    One Representation ofJavier’s Thinking 6 × 12 = (5 × 12) + (1 × 12) (Distributive prop. of x over +) = [(1 2 × 10) × 12] + 12 (Substitution property) = [1 2 × (10 × 12)] + 12 (Associative property of x) = [1 2 × (120)] + 12 = 60 + 12 = 72 Place value
  • 9.
    Unpacking The KnowledgeDemands What is the nature/category/classification of the knowledge required to… …solve 12 x 6 procedurally? …solve 12 x 6 using number sense? …understand Javier’s (and other students’) reasoning? …think to ask “How did you know that 12 x 5 is 60?” …think of a productive follow-up question to pose to Javier after he solved this task? …situate the mathematical issues embedded in Javier’s thinking in terms of the mathematics that has come before and how these ideas might unfold in future mathematics courses?
  • 11.
    Knowledge for Teaching Ball, Hill, & Bass, 2005; Hill, Sleep, Lewis, & Ball, 2007 Common Content Knowledge—the knowledge teachers are responsible for developing in students Evaluate and understand the meaning of 12 ÷ 3. Specialized Content Knowledge—knowledge that is used in teaching, but not directly taught to students Write a real-­‐life story problem that could be represented by the expression 12 ÷ 3. Pedagogical Content Knowledge (Shulman, 1986)—the ways of represenCng and formulaCng the subject that make it comprehensible to others including knowledge of how students think, know, and learn. How might children reason about this task?
  • 12.
    Unpacking The KnowledgeDemands What is the nature/category/ classification of the knowledge required to… …solve 12 x 6 procedurally? …solve 12 x 6 using number sense? …understand Javier’s (and other students’) reasoning? …think to ask “How did you know that 12 x 5 is 60?” CCK CCK, SCK CCK, SCK, PCK CCK, SCK, PCK
  • 13.
    Consider an exampleof SCK in a field other than mathematics Common Content Knowledge—the knowledge teachers are responsible for developing in students Specialized Content Knowledge—knowledge that is used in teaching, but not directly taught to students Pedagogical Content Knowledge (Shulman, 1986)—the ways of represenCng and formulaCng the subject that make it comprehensible to others including knowledge of how students think, know, and learn. Is this knowledge taught? If so, where? If not, why not? Is this knowledge assessed by researchers? How?
  • 14.
    Presentation Plan •Knowledge for Teaching and Knowledge for Teaching a Particular Subject • Assessing Specialized Content Knowledge • Rethinking Specialized Content Knowledge in a Particular Domain • Discussion
  • 15.
    Principal Investigators RandyPhilipp, PI Vicki Jacobs, co-PI Faculty Associates Lisa Lamb, Jessica Pierson Research Associate Bonnie Schappelle Project Coordinators Candace Cabral Graduate Students John (Zig) Siegfried Others Chris Macias-Papierniak, Courtney White Funded by the National Science Foundation, ESI-0455785
  • 16.
    Participant Groups (N=129with 30+ per group) PSTs, Prospective Teachers Undergraduates enrolled in a first mathematics-for-teachers content course ________________________________________________________________________________________________________________________ IPs, Initial Participants 0 years of sustained professional development APs, Advancing Participants 2 years of sustained professional development ETLs, Emerging Teacher Leaders At least 4 years of sustained professional development and some leadership activities _______________________________________________ SMSs, Strong Mathematics Students - Graduate or advanced undergrads taking advanced math courses K–3 Teachers
  • 17.
  • 18.
    Group Means byTask (0–4 scale) PST IP AP/ETL SMS Andrew ? Ones ?
  • 19.
    Group Means byTask (0–4 scale) PST IP AP/ETL SMS Andrew 1.48 ? Ones 1.58 ?
  • 20.
    Group Means byTask (0–4 scale) PST IP AP/ETL SMS Andrew ? 1.48 2.36 Ones ? 1.58 2.49
  • 21.
    Group Means byTask (0–4 scale) PST IP AP/ETL SMS Andrew 1.67 1.48 2.36 ? Ones 0.31 1.58 2.49
  • 22.
    Group Means byTask (0–4 scale) PST IP AP/ETL SMS Andrew 1.67 1.48 2.36 2.55 Ones 0.31 1.58 2.49
  • 23.
    Two ETL’s solutionto Andrew Task 1) Because he made 63 into 65 so that he could solve the problem. He got 40 and he subtracted the 2 in which he had added to simplify the problem. 2) 5 = 3 + 2 and if you only have 3 and you're subtracting 5, you can take away the 3 but you still have two more to take away, hence the -2. 63 – 23 40 – 2 38 63 - 25 -2 40 38
  • 24.
    SMS’s solution toAndrew Task Explain why Andrew’s strategy makes mathematical sense. He makes the problem simpler by subtracting 20 from 60 and 5 from 3 and adding the results. Please solve 432 – 162 = ☐ by applying Andrew’s reasoning. 432 −162 0 − 30 300 270 63 - 25 -2 40 38
  • 25.
    The Land ofSpecialized Content Knowledge The$Land$of$Specialized$Content$Knowledge$ The$Land$of$SCK$ A$Mathema2cal$Path$to$the$ Land$of$SCK$ A$Path$Through$Children’s$ Mathema2cal$Thinking$to$the$ Land$of$SCK$
  • 26.
    Group Means byTask (0–4 scale) PST IP AP/ETL SMS Andrew 1.67 1.48 2.36 2.55 Ones 0.31 1.58 2.49 ?
  • 27.
    Group Means byTask (0–4 scale) PST IP AP/ETL SMS Andrew 1.67 1.48 2.36 2.55 Ones 0.31 1.58 2.49 0.94
  • 28.
    Presentation Plan •Knowledge for Teaching and Knowledge for Teaching a Particular Subject • Assessing Specialized Content Knowledge • Rethinking Specialized Content Knowledge in a Particular Domain • Discussion
  • 29.
    Project Z: MappingDevelopmental Trajectories of Students’ Conceptions of Integers • Lisa Lamb, Jessica Bishop, & Randolph Philipp, Principal Investigators • Ian Whitacre, Faculty Researcher • Spencer Bagley, Casey Hawthorne, Graduate Students • Bonnie Schappelle, Mindy Lewis, Candace Cabral, Project researchers • Kelly Humphrey, Jenn Cumiskey, Danielle Kessler, Undergraduate Student Assistants Funded by the National Science Foundation, DRL-0918780
  • 30.
    Solve each ofthe following and think about how you reasoned. If you have time, solve another way. 1) 3 – 5 = ___ 2) -6 – -2 = ___ 3) - 2 + ___= 4 4) ___+ -2 = -10
  • 31.
    So, Why NegativeNumbers? Even secondary-school students who can successfully operate with negatives have trouble explaining. KCC Montage, High School, 2:35
  • 32.
    So, Why NegativeNumbers? Many middle-school stud ents do not understand what they are doing with negatives. Valentin, Grade 7, 1:25
  • 33.
    So, Why NegativeNumbers? Many young children hol d informal knowledge about negatives on which instruction might be based. Rosie, 1st grade, ___ + 5 = 3, 1:23
  • 34.
    One Last Reason… • Negative numbers comprise (almost) half of the reals!
  • 35.
    Why Study NegativeNumbers? • The literature that exists tends to either point out student difficulties, or offer purported instructional paths. • Too little literature documents students’ informal understandings. • Can we connect the goals of integer instruction to something other than procedures? And if so, what might that be?
  • 36.
    Ways of Reasoning Students who have negative numbers in their numeric domains typically approach integer tasks using one of the following five ways of reasoning: Order-based reasoning Analogically based reasoning Formal mathematical reasoning Computational reasoning
  • 37.
    Ways of Reasoning Order-based Analogically based Formal mathematical Computational RandyLogNec6, Grade 1, 1:11-1:43 –2 + 5 = __
  • 38.
    Ways of Reasoning Order-based Analogically (Analogy- based) Formal mathematical Computational Roland, Grade 4, 0–0:49 –5 + –1
  • 39.
    Ways of Reasoning Order-based Analogically based Formal mathematical Computational Roland, Grade 4, 0–0:48, -5 - -3 -5 – -3
  • 40.
    Teachers’ Knowledge AboutIntegers To begin to make sense of how teachers think about integers, we interviewed 10 seventh-grade teachers to determine their understanding of integers and their perspectives about teaching integers and about students’ thinking. We posed integer tasks, we asked them about their teaching, and we showed them video clips of children solving open number sentences.
  • 41.
    Research Questions 1)Do 7th-grade teachers answer integer tasks correctly, and if so, how successfully? 2) Do 7th-grade teachers invoke ways of reasoning, or rely instead upon procedures? 3) Do 7th-grade teachers recognize ways of reasoning in students? 4) How explicitly do 7th-grade teachers articulate the kinds of reasoning that they use or that students use? 5) What are the seventh-grade teachers’ goals for integer instruction?
  • 42.
    Research Questions 1)Do 7th-grade teachers answer integer tasks correctly, and if so, how successfully? 2) Do 7th-grade teachers invoke ways of reasoning, or rely instead upon procedures? 3) Do 7th-grade teachers recognize ways of reasoning in students? 4) How explicitly do 7th-grade teachers articulate the kinds of reasoning that they use or that students use? 5) What are the seventh-grade teachers’ goals for integer instruction? Yes, very successfully.
  • 43.
    Research Questions 1)Do 7th-grade teachers answer integer tasks correctly, and if so, how successfully? 2) Do 7th-grade teachers invoke ways of reasoning, or rely instead upon procedures? 3) Do 7th-grade teachers recognize ways of reasoning in students? 4) How explicitly do 7th-grade teachers articulate the kinds of reasoning that they use or that students use? 5) What are the seventh-grade teachers’ goals for integer instruction? Yes, very successfully. They invoke ways of reasoning.
  • 44.
    Research Questions 1)Do 7th-grade teachers answer integer tasks correctly, and if so, how successfully? 2) Do 7th-grade teachers invoke ways of reasoning, or rely instead upon procedures? 3) Do 7th-grade teachers recognize ways of reasoning in students? 4) How explicitly do 7th-grade teachers articulate the kinds of reasoning that they use or that students use? 5) What are the seventh-grade teachers’ goals for integer instruction? Yes, very successfully. They invoke ways of reasoning. This is mixed.
  • 45.
    Research Questions 1)Do 7th-grade teachers answer integer tasks correctly, and if so, how successfully? 2) Do 7th-grade teachers invoke ways of reasoning, or rely instead upon procedures? 3) Do 7th-grade teachers recognize ways of reasoning in students? 4) How explicitly do 7th-grade teachers articulate the kinds of reasoning that they use or that students use? 5) What are the seventh-grade teachers’ goals for integer instruction? Yes, very successfully. They invoke ways of reasoning. This is mixed. Not at all.
  • 46.
    Research Questions 1)Do 7th-grade teachers answer integer tasks correctly, and if so, how successfully? 2) Do 7th-grade teachers invoke ways of reasoning, or rely instead upon procedures? 3) Do 7th-grade teachers recognize ways of reasoning in students? 4) How explicitly do 7th-grade teachers articulate the kinds of reasoning that they use or that students use? 5) What are the seventh-grade teachers’ goals for integer instruction? Yes, very successfully. They invoke ways of reasoning. This is mixed. Not at all. Almost entirely procedural/rule-based.
  • 47.
    Brief Examples 1)Do 7th-grade teachers answer integer tasks correctly, and if so, how successfully? 2) Do 7th-grade teachers invoke ways of reasoning, or rely instead upon procedures? 3) Do 7th-grade teachers recognize ways of reasoning in students? 4) How explicitly do 7th-grade teachers articulate the kinds of reasoning that they use or that students use? 5) What are the seventh-grade teachers’ goals for integer instruction? Yes, very successfully. They invoke ways of reasoning. This is mixed. Not at all. Almost entirely procedural/rule-based.
  • 48.
    2) Do 7th-gradeteachers invoke ways of reasoning, or rely instead upon procedures? Yes, they do. Teachers invoked ways of reasoning. Even with the result unknown sentence, -3 + 6 = !, all but one invoked reasoning. Example: -3 – ! = 2 Raymond: “So I am thinking about the number line…So I am starting somewhere… and what do I do to end up at positive two? I am moving one, two, three, four, five––five units to the right.” “I am moving the opposite direction, so I would write down negative five here.” Order-based reasoning Formal reasoning
  • 49.
    3) Do 7th-gradeteachers recognize ways of reasoning in students? This is mixed. Roland, -5 – (-3) Jessica: “He seems to have a solid understanding that adding negatives to negatives gets you further away. So in his mind, he is saying, so subtracting, that must bring me closer.” Raymond: “I think he got confused. There’s no context involved…I don’t quite understand him when he used the opposite. Opposite of what? …He said, “minus minus. I don’t believe that he knows the meaning of “minus minus.”
  • 50.
    Three Implications forTeacher Integer Study • Revise the Specialized Content Knowledge About Integers
  • 51.
    Three Implications forTeacher Integer Study • Revise the Specialized Common Content Knowledge About Integers
  • 52.
    Three Implications forTeacher Integer Study • Revise the Specialized Common Content Knowledge About Integers • Consider the Challenge in Teachers’ Adopting New Goals for Integer Instruction
  • 53.
    Three Implications forTeacher Integer Study • Revise the Specialized Common Content Knowledge About Integers • Consider the Challenge in Teachers’ Adopting New Goals for Integer Instruction • Stop Seeking the Holy Grail for Integer Instruction: There is No One Best Approach or Model for Teaching Integers
  • 54.
    The relationship amongthree types of knowledge for mathematics teaching.
  • 55.