Decimal multiplication and division in mathematics textbooks for prospective elementary teachers

This study examined 11 U.S. textbooks written for prospective teachers to investigate how standard decimal multiplication and division algorithms are presented, especially the rationale of both algorithms. Analytical frameworks of various methods used in different textbooks were developed. The findings suggest that half of the textbooks do not fully present the standard algorithms. The results indicate variations in textbooks' explanations for the procedures involved in the standard algorithms. Some procedures are explained more frequently than others. The reason why moving the decimal point in both dividend and divisor keeps the quotient unchanged is provided in most of the textbooks. Half of the textbooks explain why adding the decimal places in the multiplication algorithm. However, only two books explain the rationale for placing the decimal point in the quotient. The findings suggest that textbook writers pay more attention to explaining the rationales of the standard algorithms for decimal multiplication and division.