Background: In fourth grade, students must solve single- and multi-step word problems during classroom instruction and on standardized tests. The majority of mathematics items on high-stakes assessments are word problems; thus, word-problem proficiency is necessary to demonstrate successful mathematics performance. However, many students are inadequately prepared to solve word problems. Although word-problem solving is demanding for many students, those experiencing or at-risk for mathematics difficulty (MD) often demonstrate lower word-problem performance and make significantly more errors relative to peers without MD (Kingsdorf & Krawec, 2014). Moreover, students with MD often have less access to high-quality mathematics opportunities compared to students without MD (McLeskey & Waldron, 2006). A beneficial approach for improving word-problem skills of students with MD is through schema instruction. In word-problem intervention using schemas, students first identify a word problem as belonging to a problem type and then use a specific solution strategy associated with that schema to solve the problem. Developing schemas for categorizing word problems proves valuable by helping students understand novel problems as belonging to familiar categories (e.g., Cooper & Sweller, 1987; Ng & Lee, 2009). Recognizing schemas for categorizing word problems greatly influences whether students answer problems correctly (Fuchs et al., 2014) and has been found to be more effective than other techniques for teaching word-problem solving to students with MD (Zhang & Xin, 2012). For our intervention, we also included a pre-algebraic reasoning component based on work by Powell et al. (2010, 2021) related to understanding the equal sign. Pre-algebraic reasoning skills include the ability to interpret the equal sign as relational and success with solving equations with variables, multiple operator symbols, and parentheses. Prior research suggests when students learned a relational definition of the equal sign, equation-solving performance improved, which, in turn, improved word-problem solving. Purpose/Research Question: The purpose of this study was to determine the efficacy of a 12-week, word-problem intervention for Grade 4 students experiencing MD, and to determine whether one of two approaches to multi-step problem solving was more efficacious. Students with MD were randomly assigned to (a) word-problem intervention with multiple equations, (b) word-problem intervention with a single equation, or (c) the business-as-usual control. We identified MD as students with mathematics performance at or below the 25th percentile on a word-problem measure. We asked the following research questions: What is the efficacy of a word-problem intervention focused on improving word-problem outcomes for fourth graders with MD? Is there a difference as to whether students use multiple equations or a single equation to represent multi-step word problems? Setting: We conducted this study in a large, urban school district in a southwestern state. Participants: We implemented a randomized-controlled trial to examine the effects of an intensive word-problem intervention for Grade 4 students identified with MD. After receiving approval from our university Institutional Review Board, we recruited and screened a total of 714 fourth graders. Students who performed <25th percentile on a word-problem measure (Jordan & Hanich, 2000) during screening were identified as at-risk for MD and deemed eligible for the study. Eligible fourth graders (n = 132) were randomly assigned to the word-problem intervention with multiple equations (n = 43), word-problem intervention with single equations (n = 47), or business-as-usual (n = 42). Intervention: The word-problem interventions included 36 individual lessons with the interventionist, implemented three times per week, with each session lasting 30 min. Each lesson included five activities: (1) math fact flash cards, (2) interventionist-led activities about the equal sign, (3) interventionist-led lesson featuring schema instruction, (4) schema sorting practice, and (5) cumulative review. In Activity #1, interventionists showed addition, subtraction, multiplication, and division math fact flash cards to students during two, 1-min timings. At the end of the second 1min timing, students graphed the highest score from the two trials. During Activity #2, students received instruction on solving equations and the meaning of the equal sign. To understand the equal sign as a relational symbol, students solved standard and nonstandard equations with parentheses and multiple operator symbols using concrete manipulatives, hand-drawn pictures, or equations presented with numbers and symbols. For Activity #3, interventionists provided scaffolded instruction to students to set up and solve three word-problem schemas. The intervention included single- and multi-step word problems featuring the combinations of the following schemas: total, difference, change, equal groups, and equal shares. Students in the multiple-equations intervention learned to use a separate equation for each schema within multi-schema word problems. Students in the single-equation intervention learned to use a single equation that represented multiple schemas within a multi-schema equation (e.g., (9 + 4) x 3). In Activity #4, interventionists read aloud word-problem flash cards for 1 min as students identified the problem type. In Activity #5, students participated in a paper-and-pencil review, which consisted of completing 9 fluency problems in 1 min and one word problem in 2 min. Interventionist fidelity data for the 12 interventionists was collected on >20% of sessions through in-person supervisory observations and analysis of audio-recorded sessions. After intervention, all eligible students were post-tested to determine if differences existed across the intervention and control conditions. Research Design: This study is a randomized-controlled trial with student participants assigned to conditions. Data Analysis: The data collected for this presentation is from Year 1 of a third-year study in which we collect data from three cohorts of students. We will present data collected from the 2021-2022 school year. Mulit-level modeling will be used to analyze the data once the three cohorts of data collection has occurred. Preliminary Findings: Preliminary findings indicates differences conditions on a word-problem outcome measure, F(2, 115), 22.022, p < 0.001. Contrasts indicated students receiving word-problem intervention with either multiple equations (p < 0.001, CI [4.21, 8.19]) or single equations (p < 0.001, CI [3.51, 7.71]) outperformed students in the BaU. There was no difference between active word-problem conditions, p = 0.562, CI[-1.42, 2.59].