Many general and special education teachers teach mathematics word problems by defining problems as a single operation and linking key words to specific operations. Unfortunately, teaching students to approach word problems in these ways discourages mathematical reasoning and frequently produces incorrect answers. This article lists eight common key words, identifies the operation typically associated with each, and provides 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. In contrast, other approaches do promote mathematical reasoning and substantially boost word-problem performance among students with learning disabilities. Two practices that have emerged from research studies as particularly effective for word-problem instruction are: (1) Attack strategies, which provide students with a general plan for processing and solving word problems (Montague, 2008; Xin & Zhang, 2009); and (2) Schema instruction, in which students learn to categorize word problems within problem types (i.e., schemas based on the word problem's mathematical structure), apply an efficient solution strategy for each word-problem schema, and understand the meaning of word problem language (Fuchs et al., 2014; Jitendra & Star, 2012). These strategies are discussed in detail.