Ratios and proportions that describe relationships between quantities are the foundation for students to understand and develop many concepts and skills in mathematics. Therefore, they play an important role in students' learning Mathematics. This paper will present the results of the comparison of mathematical word problems relating to proportional quantities in Mathematics textbooks of Vietnam and USA from the perspective of pattern identification. It also indicates that the design and implementation of some activities to teach the word problems in which the analysis to identify patterns is a necessary strategy. The study results revealed that using "identifying a pattern" problems is a useful tool to promote problem - solving competency for elementary school students in Vietnam.