diff --git a/src/math/calculation.js b/src/math/calculation.js
index a8d0589a7b..f0c9f4f0d3 100644
--- a/src/math/calculation.js
+++ b/src/math/calculation.js
@@ -787,7 +787,7 @@ function calculation(p5, fn) {
    *   let x = map(mouseX, 0, 100, 0, 50);
    *
    *   // Draw the bottom line.
-   *   line(0, 75, 0, x);
+   *   line(0, 75, x, 75);
    * }
    * ```
    *