Many general and special education teachers across the United States teach word problems by defining problems as a single operation (e.g., “Today, we’re working on subtraction word problems.”) and linking key words (e.g., more, altogether, share, twice) to specific operations (e.g., share means “to divide”). Unfortunately, teaching students to approach word problems in these ways discourages mathematical reasoning and frequently produces incorrect answers. In Table 1, the authors list eight common key words, identify the operation typically associated with each, and provide word problems that illustrate how reliance on key words can result in incorrect answers. Neither of these approaches—defining problems in terms of a single operation or linking key words to specific operations—has evidence to support its use.
Powell, S. R., & Fuchs, L. S. (2018). Effective word-problem instruction: Using schemas to facilitate mathematical reasoning. Teaching Exceptional Children, 51, 31–42. doi:10.1177/0040059918777250