The purpose of this study was to explore word problems as a subject matter in mathematics textbook curricula. The motivation for the study derived from the following evidence: (a) American students find some word problems are more difficult than others (Garcia, Jimenez, & Hess, 2006; Riley & Green, 1988; Stern, 2001), and (b) one of the possible mediators in students' word problem-solving performances is a limited exposure to some types of problems due to content characteristics of arithmetic textbooks (Cai & Watanabe, 2002; Fujita & Jones, 2003; Haggarty & Pepin, 2003; Tomroos, 2004).

An enriched classification of word problems (Grishchenko, 2008) was used to compare word problems across several American and Russian textbook series. Changes in first-grade word problem curricula that occurred over the last 20 years (i.e., since research conducted by Stigler et al., 1986) were identified.

Analysis revealed a diversity of word problems existing in both U.S. and Russian textbooks. The texts differ in number of problems and problem distribution across each category. Although U.S. textbooks may differ in appearance and organization, most of them are similar in their word problem curricula; i.e., in word problem distribution within the content and number of problems, which has more than doubled in the past 20 years. Russian textbooks contain more word problems (both in quantity and in variety) than American books.

This research provides insight into the word problem topic in U.S. textbooks and contributes to the research base on addition/subtraction word problem teaching and learning. It also illuminates the critical need to create equal opportunities in arithmetic word problem solving for all students.