aA
model for teaching place value: the Early Numeracy Project (ENP)
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The
ENP provides a model of number and place value learning for teachers
of children at the Year 0 - 4 levels. It is an example of cognitively
guided instruction (CGI), an approach that assumes that if teachers
understand children's thinking about specific content domains, such
as mathematics, then they can shape their lessons to better meet
the learning needs of the children (Steffe and Cobb, 1988; Carpenter
et al.,1996). As such it answers some of the concerns voiced by
researchers (Jones et al., 1996) about teachers lacking the necessary
knowledge to inform best practice. The Number Framework is divided
into two sections: knowledge and strategy. The knowledge section
describes the key items of knowledge that children need to learn,
of which grouping / place value is one. The strategy section is
divided into eight stages that describe the use of increasingly
sophisticated strategies when working with the five areas of knowledge
about number. These strategies are grouped in two parts: counting
and part-whole relationships. They are: |
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1.
Counting |
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Stage 0 - Emergent: children are not yet able to
consistently count a group of objects. |
Stage
1 - One-to-one counting: can count and form a set of objects
up to ten but cannot join or separate two sets. |
Stage
2 - Counting from one (materials): when joining or separating
sets, the objects are all counted from one and the child relies on
using physical objects. |
Stage
3 - Counting from one (imaging): as with the previous stage
but the child can work out the problem mentally. |
Stage
4 - Advanced counting: the child counts on or back from one
set when joining or separating sets. |
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2.
Part-whole |
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Stage 5 - Early additive: can see numbers as abstract
units that can be treated simultaneously as wholes or as parts of
that whole. Answers can be derived from other known facts. Strategies
used at this stage may include the Jump or Split method in addition
or subtraction. |
Stage
6 - Advanced additive: able to choose from a range of strategies
and derive multiplication facts from known facts. Strategies used
may include compensation, reversing numbers and doubling. |
Stage
7 - Advanced multiplicative: able to choose from a range
of strategies to solve multiplication and division problems. Strategies
used may include halving, doubling, place value partitioning, reversing
and multiplying within. |
Stage
8 - Advanced proportional: able to choose from a range of
strategies to solve problems that involve fractions, ratios and proportions.
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In
their survey of approximately 15 000 children, Thomas and Ward (2002,
p.13-14) found that, over the course of six months, the average gains
that children made in their ability to use place value strategies
(0.8 of a stage) were lower than in the other aspects of number knowledge.
This is shown in Table 3.1. |
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Table
1: Children who made no gains in stages over six months |
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Knowledge
areas of the Number Framework |
% |
Base Ten
System (BTS or place value) |
44 |
Stages
of Arithmetic Learning |
30 |
Numeral
Identification |
18 |
Forward
Number Word Sequence |
15 |
Backward
Number Word Sequence |
15 |
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Thomas
and Ward also found that the advances that children made in place
value strategies were greater at the lower stages of the Number
Framework. It seemed that children moved through the counting-based
levels more rapidly but that they took longer to become secure in
their understandings of collections-based or part-whole concepts.
The transition between early additive and advanced additive was,
in fact, beyond the understanding of some children. This may mean
that there might be larger gaps between the higher stages of part-whole
understanding than there are between the early stages of counting.
Children working at the Early Additive stage are operating with
2-digit numbers and then at the Advanced Additive stage are working
with numbers that contain up to six digits. Clearly, coming to grips
with these kinds of numbers will take time. Examples of the kind
of problem-solving that children are doing at these stages are:
Example 1 (Early
Additive): addition of two- or three-digit numbers. The groupings
and strategies that could be used, |
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e.g.
43 + 25a |
= (40 + 20) + (2 + 5) (Split method) |
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=
43 + 20 + 5 (Jump method) |
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= 40 + 28 (Tidy numbers) |
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Example
2 (Advanced Additive): using place value strategies with larger numbers,
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e.g.
273 -106a |
= (273 -100)
-6, |
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forward and backward
counting in 10s,100s,1000s |
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ordering numbers
up to a million. |
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Thomas
and Ward (2002) found that older children who started later made greater
gains than younger children thus suggesting that there may be a link
between age and number concept development. Older children have more
background information with which to understand new concepts. This
suggestion is in agreement with the cautions made by Kamii (1986)
about the dangers of attempting to teach place value concepts too
soon. |
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aA
critique of the Numeracy Project |
The
literature suggests a number of aspects relevant to the ENP model
that may hinder children's understandings of place value. These are:
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a focus on unitary (counting by ones) concepts, |
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children not having ownership of place value concepts, |
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an emphasis on conscious thinking skills at the expense of other forms
of thinking, |
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too much stress on strategies and procedures and |
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the stages model of learning upon which the ENP is based. |
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Counting
strategies take up the first four stages of the Number Framework
before children engage in part-whole thinking. As Cotter (2000)
has suggested, this emphasis on counting by ones may interfere with
the development of place value concepts. When a child uses a counting-based
strategy to count a collection of objects by ones, he or she may
lose the idea of the whole. By focusing on counting first it may
be difficult to then integrate ideas about the part-whole nature
of multi-digit numbers. Because of this, as well as because of the
irregularities of the English language, children may remain stuck
in thinking of multi-digit numbers as collections of ones rather
than moving on to a concept of parts and wholes.
The
children do not own the concepts that are contained in the Number
Framework. The model that is embedded within it comes from the levels
of conceptual development derived from the work of researchers,
not the children themselves. As such, it is not a constructivist
approach to learning. Fuson et al (1997) reported that after participating
in classes where the learning of multi-digit concepts and procedures
were treated as problem-solving activities, children did show significant
gains in understanding about place value. The key element in the
lessons that they observed was that the children were encouraged
to come up with their own solutions, rather than relying on instructions
on how to use procedures and rules.
Conscious
thinking skills, which can be articulated by the child, are emphasised
in many schools (Claxton, 1997). Claxton differentiates between
conscious and unconscious thinking: in the former, reason and logic
are used and articulated whereas in the latter, unconscious thoughts
can lead to intuitive knowledge. He argues that intuition as a valid
way of thinking has been neglected in schools. Slower types of thinking
or contemplation, while not infallible, are better suited to understanding
complex or ill-defined situations. As a result of repeated observations,
the child gradually uncovers patterns that are embedded in, or distributed
across, a wide variety of experiences. Perhaps the development of
deep place value knowledge may be fostered by an intuitive, unconscious
process as well as by an explicit conscious way of thinking. Encouraging
children to explain their thinking, according to Claxton, may hinder
concepts that are slowly developing in the unconscious mind.
The
Number Framework sets out stages of learning about the number system.
Within these stages, children are taught strategies to help them
think about and solve number problems. Haskell (2001) claims that
teaching strategies is insufficient because learning by this method
is too often restricted to the context within which it was experienced.
It makes little use of the prior learning of the child. He says
that teaching that promotes transfer of learning to problems outside
of the initial context involves looking at an idea or procedure
many times in different ways, on different levels and contexts and
in different examples. This supports the thinking of Claxton (1997)
about the gradual building up of intuitive knowledge through the
observation of patterns and examples. The ENP encourages teachers
to make links for the children when they are discussing concepts.
Haskell warns that although providing examples is important, it
may increase procedural efficiency at the expense of a deep conceptual
knowledge base. The examples may make the children more expert in
“doing” problems without having to really understand the concepts
that lie behind them. Children become proficient at problem-solving
within the confines of the examples given but may not develop a
broader understanding of the concepts as they present themselves
in other settings. Greeno (1991) argues that mastery is more than
the ability to convert a form of skill: it is characterised as global,
transferable, flexible and owned by the learner.
The
Diagnostic Interview is an assessment tool provided for teachers
in the ENP. It enables them to group children within the stages
of the Number Framework. Children are interviewed on a one-to-one
basis with a bank of activities designed to show their level of
number knowledge and skill. The measurement of knowledge using a
stages approach is problematichowever, as it is difficult to measure
the extent of knowledge that may lie between the stages. By defining
a set of skills and knowledge in a teaching model and then assessing
against them the teacher is at once limiting the possibility that
the child can demonstrate a breadth of learning that is outside
of the model. Children may have progressed laterally and this may
not feature in the assessment.
The
difficulty that children appear to have in moving from the Early
Additive to the Advanced Additive level as reported by Thomas and
Ward (2002) could perhaps be a consequence of the focus on learning
strategies and getting to the next stage, rather than exploring
concepts from a broader base. Perhaps the children need more time
to construct their own ways of knowing before they can progress
to the more expert levels of the Number Framework. Social constructivists,
such as Greeno (1991) argue that learning is more than strategies:
it is encouraged by exploring, relating and creating understandings.
Greeno
(1991) argues that little has been proven about the way that learners
progress from a level of learned competence to that of automatic
expertise and suggests that lesson sequences other than those based
on stages models may need to be considered. In order to understand
more complex ideas Ertmer and Newby (quoted in Mergel) assert that
a constructivist perspective is more effective. Clay (2001), commenting
about reading, describes how children begin to use more than one
strategy or resource simultaneously to problem-solve, using different
types of information and showing alternative ways of using information.
This model of learning is relevant to the development of place value
concepts and describes an increasingly unconscious or automatic
expertise. As a dynamic, exponential process, the idea of the sequential
learning that is assumed by a stages approach becomes untenable.
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aConclusion |
Looking
towards the interviews I was interested to see whether aspects of
the literature review and the critique of the ENP model might or
might not be borne out. It was possible that the two groups of children
would reveal completely different knowledge and skills. These might
give insight into the initial unitary focus of the ENP (where children
start with counting-based knowledge before they move on to a part-whole
way of thinking) and how this might hinder their place value concept
development. The activities that I planned to give to the children
might also provide data to suggest that the children owned their
own concepts of place value rather than merely copying procedures.
This could be revealed by the amount of flexibility that I observed
in their attempts to problem-solve. The data might also reveal that
children showed intuitive ways of thinking and also how the stages
model, upon which the ENP is founded, fits with the conceptual development
that I was able to observe. |
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