
in the presentation, description and 
operationalisation of the concept (R). The analysis 
of word problem, together with the study of the 
processes and symbolic representations used by 
students when discussing and solving word 
problems, is the key element of the above-mentioned 
theory (Vergnaud, 1991).     
Vergnaud (1986, 1991) asserts that, in order to solve 
a word problem, one must employ a great number of 
theorems, i.e. knowledge equivalent to the properties 
of a concept. When doing so, one resorts to abilities 
and knowledge that Vergnaud (1986, 1991) names 
theorems-in-action. In short, theorems-in-action 
refer to representations of the relevant aspects of the 
action in question. Indeed, these representations 
reveal only the essential aspects of the action.   
In more practical terms, one could speak of concrete 
elements (such as sticks, marks on paper, fingers) as 
the invariables employed. Since the response offered 
would certainly not be the quantity of material used, 
but rather the quantity about which the question asks 
through the representation, the objects used are not 
relevant; instead, what matters is the result.  
Although word problems are worked on all through 
elementary and secondary school, their diversity is 
not fully explored as that would require the use of 
numerous situations involving countless invariables. 
What one normally does use is a limited range of 
additions, subtractions and properties of these 
operations. Similarly, the number of forms of 
symbolic representations of these operations is also 
limited (e.g. Charlie has 6 cars and Paul has 8. How 
many cars do they have altogether?). This kind of 
limited work makes students employ a reduced 
amount of specific knowledge and present 
difficulties when solving other problems which, in 
turn, require the use of different meanings, 
properties and representation forms.  
An instance of word problem characterised by 
change would be the following: “Mary used to have 
14 letter papers. Her mother gave her 8 more. How 
many letter papers does she have now?”, whereby a 
change happens to an initial number, resulting in a 
new number. In other words, an initial number goes 
through a direct or indirect transformation, causing 
this initial number to grow either bigger or smaller. 
As we can see, the idea of time is implicit in a word 
problem like this one, making it an invariable that 
needs to be taken into account in order for one to 
find the solution.          
Vergnaud (1986) divided addition and subtraction 
problems – isolated or combined over  natural, 
integer or real numbers sets – into six categories. 
Carpenter and Moser (1982), as they explore natural 
numbers only, divided the problems on four 
categories: combination, comparison, change and 
equalisation. These 4 categories give rise to 16 
different situations, depending on where the 
unknown number is located.  
The Carpenter and Moser (1982) classification was 
adopted by Leite, Borba and Gomes (2008), which 
proposed a help-function using a different  diagram 
form for each one of the four problem categories. 
4 VIRTUAL ENVIRONMENTS 
AND THEIR MULTIPLE 
REPRESENTATIONS: 
SUPPORT TO TEACHING AND 
LEARNING ONCLUSIONS 
The Theory of Multiple External Representations 
(Ainsworth, 2006) is a cognitive theory that 
advocates the use of specific techniques to represent, 
organise and present knowledge. MERs have the 
following three key functions: complementary roles, 
constrain interpretation and construct deeper 
understanding.  
The first function, “complementary roles”, 
explores representations that, for being of different 
types, complement each other and offer support to 
the cognitive process. The main objective of the 
“constrain interpretation” function, on the other 
hand, is to use representations that helps the learner 
to avoid misintrepretations about the concepts in 
question. Finally, the “construct deeper 
understanding” function uses MERs as a tool for 
helping the learner to buid abstractions about the 
concept and organize it in a higher level.  
According to Ainsworth (2006, 2008), 
representations may appear simultaneously or 
alternately. Either way, learners must be able to 
understand the form of representation, its relation to 
domain, how to select an apropriate form of 
representation and how to create an appropriate one 
(Ainsworth, Wood, Bibby, 1996). This way, one can 
construct new representations and access other 
representation options which, in turn, help expand 
the conceptual field in question.  
Having a wide range of representations may 
result in more effective learning conditions, 
particularly when these representations provide 
learners with a more in-depth view of the concept in 
question, or when they suit the user’s cognitive 
model. Furthermore, making use of more than one 
representation type may help grab the students’ 
attention for longer (Ainsworth, 1999). 
A USER-INTERFACE ENVIRONMENT AS A SUPPORT IN MATHS TEACHING FOR DEAF CHILDREN
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