Got an exam as a PDF and need to change a few questions? The plain text converts easily; the math is where the time goes. After converting, roots, fractions, integrals and systems of equations often turn into images, scrambled characters, or vanish altogether. This post compares the usual approaches and how to keep equations editable.
Why do equations break when converting a PDF?
A PDF only stores where each character and stroke sits on the page — not “this is a fraction” or “this is a superscript”. A converter has to guess the structure back from the shapes. That works for ordinary text; with multi-level math (a root inside a fraction, integral bounds, matrices) wrong guesses are common. Scanned PDFs are harder still, because the text has to be recognized (OCR) first.
Option 1: Open the PDF in Word
Word can open a PDF (File → Open) and turn it into an editable document. It's quick and needs nothing extra, which suits mostly-text documents. For math exams, equations usually come out as loose characters or are kept as pictures — they look right but can't be edited.
Option 2: Online converters
Free PDF-to-Word sites keep the layout fairly well and many offer OCR for scans. But they're built for general documents and don't understand math: equations come out as plain text or images, not MathType or Word Equation. Keep in mind the exam is uploaded to a third party's server.
Option 3: Ask an AI
ChatGPT, Gemini and Claude can read PDFs and rewrite the content with LaTeX equations. Short exams turn out well, but you still have to get the LaTeX into Word, the AI tends to skip or summarize long documents, and tables and figures usually don't survive. If you want to try, use the PDF to Word prompt so the AI answers in the right format.
Option 4: MathCopy — PDF to Word with equations intact
MathCopy's PDF to Word feature is built for math documents:
- Equations come out as MathType (default) or Word Equation — double-click to edit.
- Variation tables, data tables and figures stay in place.
- Pick the pages, e.g. “1-5, 8”; only those pages count.
- Reads scanned PDFs too; failed conversions don't use pages.
- Every computer gets 10 free pages to try it.
Quick comparison
| Approach | Equations afterwards | Tables, figures |
|---|---|---|
| Open in Word | Loose characters or images | Partly kept |
| Online converter | Plain text or images | Fairly good |
| Ask an AI | LaTeX, still to convert | Often lost |
| MathCopy | MathType or Word Equation | Kept in place |
Tips for better results
- Use the original PDF rather than a screenshot; the sharper the scan, the better.
- PDFs using old Vietnamese fonts (like .VnTime) can garble accents — check the text afterwards.
- Pick only the pages you actually need to edit, to save time and pages.
- Click a few equations to confirm they're MathType/Equation before printing.
Convert PDF to Word with MathCopy
MathType or Word Equation, tables and figures kept — 10 free pages on every computer.