# Wiskunde — wiskunde.sofie.be

> Wiskunde is a free, multilingual, ad-supported (Google AdSense Auto Ads only — no tracking SDKs, no third-party profiling cookies before consent) website where **children and adults** practice math: multiplication and division tables, addition, subtraction, products, quotients, number splits, units of measure, and more. Endless, randomly generated exercises with three difficulty levels plus a custom range mode. EU/GDPR-first, child-safe.

Owner: Sofie.be — Sofie De Valck, Rauwakker 7, 1745 Mazenzele, Belgium · VAT BE0823170308 · info@sofie.be · parent site https://sofie.be/

## URL structure
Every page is available under a language prefix and uses a localized slug for full multilingual indexing:

- `/{lang}` — home
- `/{lang}/{page-slug}` — static pages (about, contact, privacy, cookies, terms, legal)
- `/{lang}/{practice-slug}/{exercise-slug}` — practice exercise
- `/{lang}/{overview-slug}/{exercise-slug}` — reference overview (tables grid, unit conversions, etc.)

`{lang}` ∈ `nl`, `en`, `fr`, `de`, `es`, `it`, `pt`. Every URL is listed in `/sitemap.xml` with `xhtml:link` hreflang alternates.

## Example URLs
- Dutch home: `/nl` · English home: `/en` · French home: `/fr`
- Multiplication tables: `/nl/oefenen/tafels` · `/en/practice/tables` · `/fr/exercices/tables-multiplication` · `/de/ueben/einmaleins` · `/es/practicar/tablas-multiplicar` · `/it/pratica/tabelline` · `/pt/praticar/tabuadas`
- Privacy: `/nl/privacy` · `/en/privacy` · `/fr/confidentialite` · `/de/datenschutz` · `/es/privacidad` · `/it/privacy` · `/pt/privacidade`
- Overviews: `/nl/overzichten/tafels` · `/en/overviews/tables` · …

## What learners can practice
- Multiplication tables (1–12) · Division tables
- Addition (sum) · Subtraction (difference)
- Product · Quotient
- Number splits · Units of measure (length, weight, time, volume, distance)
- Custom range mode: practice e.g. only the tables of 4 and 5, or sums from 1 to 100

## Languages
Dutch (nl), English (en), French (fr), German (de), Spanish (es), Italian (it), Portuguese (pt).

## Discovery files
- `/sitemap.xml` — every (language × page) URL with hreflang alternates
- `/robots.txt` — AI crawlers explicitly allowed
- `/ads.txt` — Google AdSense publisher verification
- `/.well-known/security.txt` — responsible disclosure contact
- `/llms-full.txt` — full LLM context

## Principles
- Free to use · funded only by Google AdSense Auto Ads
- No account required · no personal data collected
- EU/GDPR-, ePrivacy- and Belgian-law compliant
- Suitable for children AND adults
- Client-side question generation (works offline-friendly)