Four Nines
Play the classic four 9s puzzle as a free daily math game. Combine four copies of today's digit with +, -, ×, and ÷ to hit the target. No sign up.
Free to play in your browser — no download, no sign up.
How to play
- Use exactly four copies of today's digit — no more, no fewer. The daily rotates through 1 to 9; nines are the house canon.
- Combine them with addition, subtraction, multiplication, and division, using parentheses to control the order of operations. Decimals, concatenation (like 99), and square roots appear when a puzzle allows them.
- Build an expression that equals the target number exactly.
- Find any solution first, then hunt for a shorter or more surprising one.
Example solutions
(9 + 9) / (9 + 9) = 1— A balanced fraction turns four identical numbers into one.9 / 9 + 9 / 9 = 2— Two simple fractions make a tiny target.(99 - 9) / 9 = 10— Concatenating two 9s opens up larger intermediate values.99 + 9 / 9 = 100— The most famous four nines solution of them all.
Stuck on a number? The Four Nines solver has verified solutions for every target from 1 to 100 — for example, making 100 with four 9s.
FAQ
What is the four nines problem?
It is a classic math puzzle, also called the four 9s puzzle: using exactly four 9s and arithmetic operations, write an expression that equals a given number. For example, (9 + 9) / (9 + 9) = 1 and 99 + 9 / 9 = 100. Four Nines turns the classic problem into a daily game: four copies of one digit — the calendar picks it, nines are the canon — and one new target every day.
How do you play Four Nines?
Each day there is one digit and one target number. Combine exactly four copies of that digit with addition, subtraction, multiplication, division, and parentheses to build an expression that equals the target. Order of operations counts.
Why is it called Four Nines if today's digit is a 7?
Nines are the canon: the classic problem this game grew from uses four 9s, and the solver and target pages here run entirely on 9s. The daily deals four copies of one digit from 1 to 9 so the habit stays interesting. The name stays — it is the brand, and 'Four Sevens (Some Days)' is not a name.
Do I need advanced math?
No. The daily puzzle is pure arithmetic: +, -, ×, ÷, and parentheses. The challenge is in arranging them, not in knowing anything fancy.
Can there be more than one answer?
Yes. Many targets have several valid expressions, and finding a shorter or stranger solution than your first one is half the fun.
Is Four Nines free?
Yes. Four Nines is free to play in your browser on burger fun — no download, no sign up, no account.
I searched "four nines" looking for 99.99% uptime.
Wrong kind of four nines — that one is an availability target, this one is a daily math puzzle. Ours is more fun than an SLA, permits unlimited downtime, and you are welcome to stay.
The Number Lab
Same idea, different constraints: four 9s, four 4s, or any four digits you like.
- Four Nines — the daily puzzle (this page)
- Four Nines solver — every target, solved
- Four Fours — the 1881 original
- Four Fours solver — including the impossible five
- Make 24 solver — any four digits
- Today's 24 — one new hand a day