A learning book is one of the teaching materials frequently used by
students in order to help learning activities.This research used Research and
Development method. The objectives of the research are to identify: 1) the factual
condition of teaching material use in elementary schools, 2) the development of
teaching materials using calculator through direct teaching method, 3) the
appropriateness of teaching materials using a calculator withdirect teaching
method, 4) teachers response on teaching materials using calculator through
direct teaching method, 5) students response on teaching materials using
calculator through direct teaching method. The factual condition of teaching
materials, as learning supporting facilities at school, in SD UMP still has
limitations and has not had guidance about the use of calculator in the guiding
step of Mathematics skill. Therefore, the development of this skill is required. The
development process of the teaching materials used Borg and Gall model,
consisting of potential and problems, collecting information, product design,
design validation, design improvement, product trial, product revision, field trial,
product revision, and product massive production. The product of Mathematics
teaching material consists of materials about circumference and plane figure
area, which is implemented in semester 2 of grade 4. Moreover, the product is
also supported with the procedures of using a calculator and the implementation
of good direct teaching method. The validated book teaching materials obtain an
average score of 4.5 (highly valid). The teachers response, either in SD Negeri
Pliken 2 or SD UMP, on the development of the teaching materials, obtains an
average score of 4.3 (excellent). Meanwhile, the students response on the
development of the teaching materials obtains an average score of 4.23
(excellent) for SD UMP students and 4.8 (excellent) for SD Negeri 2 Pliken
students. Based on the results, it can be concluded that the developed teaching
materials can be effectively used in SD UMP.