Observed arrival · 2026-11-13
Problemyriad: 10,050 problems, with hints
A Japanese-language study site presents math and science problems organized by subject and topic, with hints and explanations.
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- For
- Japanese-language math and science learners
- Worth noticing
- Its topic list reaches graduate mathematics, including knot theory, category theory, and optimal control, alongside school science.
Field notes
The homepage organizes material by school stage and unit, from arithmetic and junior-high mathematics to graduate topics such as category theory, knot theory, and optimal control. It also lists middle- and high-school science, plus university physics and chemistry. Visible controls offer search, resuming, unit selection, and new, random, or popular problems; the page describes hints revealed one at a time and explanations.
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◎NicheUnusually specific use
One card from the complete issue