The purposes of this study are  to determine: (1) Student’s representation
of represent sequence of numbers based Bruner’s representation (2) Activity of
student’s abstraction in represent sequence of numbers based Bruner’s
representation. 
This study uses qualitative descriptive method. The study is conducted in
SMP Muhammadiyah 2 Surakarta on the VIIIA. Data in this study is obtained
from the results of tests based on student interviews. Subjects are taken with
purposive sampling technique  as much as 8 students. Data analysis is done
through reviewing all data, reducing data, collating data in units, and checking the
validity of the data. Data validation is done by triangulation of time. Data about
student’s representation and Activity of student’s abstraction in represent
sequence of numbers based Bruner’s representation is conducted by interviewbased
test.
Students’
answers
are
analyzed
to
student’s
representation
and
Activity

of

student’s abstraction in represent sequence of numbers based Bruner’s
representation.  
 The analysis of data results: (a) Group I consists of subject WS, HA, DR,
and AT. Subject in this group is achieve symbolic representation but they can’t
make a generalization. (b) Group II consists of subject EN and HN have achieved
symbolic representation and make a generalization. (c) Group III consists of
subject IQ and RO that in enactive representation. Activities of student’s
abstraction that represent sequence of numbers  are (a) Identification the problem
(b) Find the conclusion from every case (c) Identify the  sequence of numbers
based with picture (d) Find the conclusion through imagine from the picture and 
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that experiment (e) Make a picture, flowchart or list name from the problem that
given. (f) Find a relation from its conclusion (g) Make a hypothesa (h) Write the
sequence of numbers (i)  Applicate the sequence of numbers to solve the problem
(j) Calculate the problems (k) Make a relation from every representation (l)
Generalize