The Elimination Scratchpad

Instructor link builder 1–4 equations · 1–4 variables URL + PreTeXt exact fractions

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Instructor tool

Build a textbook-activity link

Opening the Scratchpad without activity options brings you here. Enter an augmented matrix with at most four equations and four variables, or use Codex to generate the URL options from a textbook screenshot or source. The selected goal supplies the multiple-choice sequence automatically.

Activity number

Goal

Equations

Variables

Variable names Comma-separated names; the number must match the variable count.

Back-to-notes URL A full URL or a relative textbook path. The activity’s top button returns here.

Complexity audit

Ready.

REF · pivot

Choose the next step in this elimination route.

Pick an answer.

Scroll to see all columns.

System as equations

Use Left and Right Arrow to read the full expression.

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Activity complete

0 questions · 0 misses

About The Elimination Scratchpad

Purpose: This activity player loads a small augmented matrix from a textbook link and follows a goal-dependent sequence of Gaussian or Gauss–Jordan elimination questions, entirely through multiple choice. This course uses leading 1s in REF.

Link builder: Opening the file without activity options opens the instructor tool. Adding ?author=1 also forces this view.

Version: The Elimination Scratchpad [v0.4(beta)]

Copyright: © 2026 Sébastien Roch

Code license: MIT. Instructional content: CC BY-NC 4.0, except where otherwise noted.

Privacy: The file stores no scores and sends no activity data anywhere.

Acknowledgments: Thanks to Jingyi Li for helpful feedback.

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