Development of Study Peripheral Base on the Realistic Approaches to Increase Ability of Mathematical Reasoning of Student Junior High School State 6 Medan

The aims this research are: (1) Knowing valid
developed learningdevice using realistic, (2) Knowing practical
developed device Learning uses realistic (3) Knowing effective
developed learning devices using realistic approach to the
comparison material, (4) Knowing the increase in mathematical
penalty ability students use learning tools developed with realistic
learning on the proposed material, This research is a
development study using modified Thiagarajan, Semmel and
Semmel (4D) development model. Trials were conducted twice
the first (trial I) in class VII-1 and (trial II) in class VII-k. The
results of this study indicate: (1) The validity learning devices
according to expert teams is valid (2) Learning devices meet the
practical criteria, namely the assessment experts and
practitioners of learning devices in general is good and can be
used with a slight revision and ability of teachers to manage
learning obtained an average 4.08 in category good (3) Learning
devices meet the effective criteria classical completeness reaching
86.6%, achievement objectives is 80%, 75.8%, and 75%, student
responses to learning are obtained average 90.59%, and learning
time does not exceed normal study time. (4) Improvement
mathematical reasoning abilities seen from the value of N-gain
that is 0.44 in the category of “moderate”.