Sum Slider is a puzzle game where students slide numbered tiles along preset paths to place them on target lines so their totals match a given sum. As players move the tiles, a sum tracker updates dynamically, helping them monitor how close they are to the goal. Early levels focus on simple addition using single lines, while later challenges introduce intersecting paths, multiple lines that must each reach their own target, and the ability to swap numbers along the path to create new combinations. Eventually, negative numbers appear, allowing students to explore more complex operations and deepen their understanding of additive reasoning. Throughout play, students use number sense, strategic thinking, and flexibility with operations to plan moves, make adjustments, and verify their results.