EARCOME4, 2007 LP022
Table 2: Student’s strategies in four representations
Type of Representation
Grade 3
Correct(Incorrect)
Grade 4
Correct(Incorrect)
Grade 5
Correct(Incorrect)
Total
Correct(Incorrect)
1.Word
32(51)
40(40)
56(33)
128(124)
2.Table
0(0)
4(0)
4(4)
8(4)
3.Graphic
22(16)
13(11)
16(6)
51(33)
4.Symbolic
0(1)
0(0)
11(3)
11(4)
Total
54(72)
57(51)
87(46)
188(165)
Notes
There are 3 students who simultaneously use words and symbols to present the answers.
There are 4 students who simultaneously use words and symbols to present the answers.
There are 6 students who simultaneously usewords and symbols to present the answers; There are 2 students who simultaneously usewords and symbols to present the answers.
By comparing the correct against the incorrect strategies, it is found that the students’ understanding of the problem and relationship between the variables seems to be the key point of solving the unknown numbers. Most students tried to use words and graphic symbols to explain and find the relationship between the variables. Analysis of the results shows that most students used words and graphic representations, but the percentage of success and failure of the problem-solving is nearly the same (about 90%). That means some people pass the barrier of understanding the problem, but there are the same percentage of students still exploring. More importantly it demonstrates that to solve algebraic problems, one need to understand the problem and the relationship between the variables. This is also emphasized during the process of algebraic teaching. The outcome that the students presented matches the key points of the algebraic teaching which Kaput (1998)、Schliemann、Carraher and Brizuela (2007) emphasized.
Moreover, by comparing the results, it is found that the application of symbols can help to solve the problems. There are 15 students who used this method. Among them, 11 students solved the problem correctly. The use of this method acquired high percentage of success. This means that algebraic symbol is an effective problem-solving tool and can be taught to the students. This phenomenon is consistent with the finding which Davydov (1991) and Bodanskii (1991) stated. From the analysis, though only the fifth grade students correctly applied the symbols to solve the problem, it doesn’t mean that the third and fourth grade students were unable to do it. Regarding this issue, we can explore it in future research.
Analysis of description in children’s algebraic reasoning process
This section explores how the students use representations to proceed to their algebraic reasoning through the use of the above four representations to get the right answers.
(1) Solution in word representation
Students adapting word representation to solve problems use four steps illustrated as follows:
A. Word representation complied with mono-solving method. (See Fig 1)
Students randomly found a set of variables (6 cars, 4 bikes), then complied with drafting to check calculation. Analysis of their strategies suggested that students grasped the idea that the sum of the vehicles and the number of wheels would not change. Calculation was then done to prove that this set of variables meet the requirement of the problem.
B. Word representation complied with any method to solve problem. (See Fig 2)
Students viewed the 10 vehicles in the parking lot as cars, thus the number of the wheels is 40.Then they used random calculation (For instance 32 – 24 = 8, 8 ÷ 2 = 4) and found it difficult to fulfill the requirements of the problem. Therefore, they complied with symbols by using circles to represent the wheels. Through random combination for several times, they found the correct answer. During this process, students made use of these symbols that represent the wheels to determine the number of vehicles.
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