The purpose of this study is to investigate, via a model, the explanatory and predictive relationships among the
following variables: Mathematical Problem Solving and Reasoning Skills, Sources of Mathematics Self-Efficacy,
Spatial Ability, and Mathematics Achievements of Secondary School 8th Grade Students. The sample group of
the study, itself conducted using a survey model, consisted of 470 8th grade students aging between 14 and 15
years old attending different secondary schools in the city of Konya, Turkey and its surrounding area. Of the total
students, 238 were female (50.6%) and 232 were male (49.4%). In the study, the Scale of Sources of Mathematics
Self-Efficacy was used to determine students’ levels of self-efficacy; the Problem Solving Test was used to
measure their problem solving skills; the Reasoning Test was used to measure their reasoning skills; both the
Mental Rotation and the Paper Folding Tests were used to measure their spatial skills; and the Mathematics
Achievement Test was used to measure their level of mathematics achievement. The data collected in the study
were analyzed using one of the Structural Equation Models, that being the Structural Regression Model. According
to the results obtained, the variables Sources of Mathematics Self-Efficacy, Spatial Ability, and Problem
Solving and Reasoning Skills were witnessed to account for 75% of the variation in mathematics achievement.
These variables have a considerable effect on mathematics achievement. Knowing this, it is recommended that,
in order increase mathematics achievement, a mathematics teaching model in which these interrelated variables
coexist be developed and then implemented in activities supporting self-efficacy