to help students understand probabilities. The purpose
of this research was to obtain the learning trajectory
in probability learning using snakes and ladders
games using PMRI approach and to determine the
role of snakes and ladders games in learning
probabilities.
2 LITERATURE REVIEW
2.1 Pendidikan Matematika Realistik
Indonesia (PMRI)
PMRI is an adaptation of Realistic Mathematics
Education (RME), a learning theory developed in the
Netherlands since the 1970s by Hans Freudhental.
Two important views from Freudenthal are: (1)
mathematics must be connected with reality and (2)
mathematics as human activity (Zulkardi & Putri,
2010). Gravemeijer (1994) states that the role of a
teacher must change from a validator (stating whether
the student's work and answers are right or wrong),
being a person who acts as a mentor who appreciates
each student's contribution (work). The main
principles of PMRI are as follows (Gravemeijer,
1994; Zulkardi, 2002; Zulkardi & Putri, 2010):
a. Guided reinvention and progressive
mathematizing
Guided discovery and progressive mathematics
can mean that students are given the opportunity
to experience the same process when mathematics
is found. The teacher guides students to move
from one level to another level of mathematical
thinking.
b. Didactical phenomenology
Situations that contain the phenomena that are
used as material and application areas in teaching
mathematics must depart from the real conditions
of students before reaching the formal
mathematics level.
c. Self-developed models
The principle of model development has a very
important role for students. The role of the
principle of the development of the model itself is
to bridge students from real or concrete situations
to abstract situations, or from the informal stage
to the formal stage of mathematics. This means
that students make their own models in solving
problems from situations that are close to the
nature of students, for example the use of the
context of snakes and ladders games that are
involved in learning mathematics to find concepts
in the material probabilities for an event.
The principles of PMRI above can be explained
more broadly through their characteristics. The five
characteristics of PMRI (Zulkardi, 2002; Zulkardi,
2005; Zulkardi & Putri, 2010): (1) Use of contexts for
phenomenologist exploration. (2) Use of models for
mathematical concept construction'. (3) Use of
students' creations and contributions. (4)
Interactivity. (5) Intertwining mathematics concepts,
aspects, and units.
2.2 Probability
There are 4 competencies in the subject matter of
probability, namely: understanding randomness,
sample space, comparing and measuring
probabilities, and understanding correlations or
relationships between events (Bryant & Nunes,
2012). According to Coladarci (2011: 175),
probability theory is the possibility of certain events
occurring. The possibility of the emergence of the
front side of throwing a coin as much as once is 0.5.
Because there are only two possible outcomes when
throwing a coin. Thus an probability is a comparison
that is between 0-1 denoted by p. The chance of an
event A is the result of the number of sample points
for event A with the number of members of the event
sample room A, formulated as Equation (1).
𝑃𝐴 𝑛𝐴/𝑛𝑆 (1)
2.3 Snakes and Ladders Games
The snakes and ladders games is a board game for
kids that is played by two or more people. The board
of snakes and ladders is divided into small boxes and
some boxes are drawn by a number of "ladders" or
"snakes" that connect them to other boxes (Yumarlin,
2013). The snakes and ladders games is played on a
board with a 10x10 grid, a sequence number in a
zigzag pattern from 1 (beginning, in the lower left
corner) to 100 (end, in the top left corner). At various
locations on the board are snakes and ladders placed,
each or connecting a pair of boxes. All players start
outside the board and take turns rolling the dice and
moving according to the dice that appears. If the
settlement moves at the foot of the ladder, then go
straight up. Also, if you move above the snake's head,
you are forced to slide to the snake's tail to the
previous square. there is no consequence of landing
on a ladder or snake tail. Snakes and stairs are one
way of mathematical parts, this is called a directed
graph. The first players to reach the 100 box win
(Berry, 2012; Connors & Glass, 2014). This game
was created in 1870. There is no standard board game
in snakes and ladders, so everyone can create the