The study aims to explore how the mathematics teachers taking post-graduate education use their Algebra knowledge for the expression, "You can't add apples and pears" that is expressed in almost every segment of the society, in creating mathematical content. The data of the research consisted of the written answers of the thirty-seven (37) teachers, who had taken the Algebra Teaching course, to the question "There is a rule in mathematics as everyone says; explain the statement 'You can't add apples and pears' mathematically" in the exams from the 2008-2009 academic year to, including 2015-2016 academic year. The participants took the algebra education in the courses named Algebra and Introduction to Algebra courses and sufficient algebra education was provided to answer the question in the courses. The document analysis method was employed in the study and the data were analyzed with the descriptive content analysis. The results indicated that most of the teachers were aware of their algebra knowledge, the number and quality of the mathematical contents in the answers were at a satisfactory level, but the visuals used in some contents were not appropriate.