7-Day Coin Detective Streak
Examine one coin each day and note its date, design and what is on each side. Check in daily.
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History · Facts & stats · iChallenge network
Daily facts and stats about coins, minting and coin history, plus real challenges to put them to work.
What is the blank metal disc called before it is struck into a coin?
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One ranked attempt per day. Practice as much as you like.
Join one, log your days or post your proof. Finishing earns XP and the Finisher badge.
Examine one coin each day and note its date, design and what is on each side. Check in daily.
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Flip a coin 100 times, record heads and tails, and compare with the expected 50/50. Post your results.
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Make pencil rubbings of several different coins on paper. Share a photo link or a short write-up.
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Live counts from CoinChallenge.com. All arena stats →
Earned on any arena, shown on your profile everywhere.
Add your email to keep your level, streak and badges if you switch devices, and carry them to every iChallenge arena. One email when you save; no spam.
Fund a prize on CoinChallenge.com and your brand sits on the challenge card, the leaderboard and every finisher's share. Prizes only appear once they're funded, so players can trust what they see.
No — knowledge games only. Nothing here is financial advice.
Only when a sponsor funds a prize. Funded prizes and their rules are shown on the challenge card; otherwise you play for rank and badges.
Everyone on this arena gets the same five questions each day, from easy to hard. You get one ranked attempt; practice rounds are unlimited.
100 points per correct answer, up to 50 more for answering quickly, a combo multiplier for answers in a row, and 150 bonus points for a perfect round.
Yes. Playing, streaks, badges and leaderboards are free. Some challenges carry a sponsor-funded prize; the challenge card shows it when one is funded.