BIN, OCT, DEN & HEX – Test Your Number Conversion Skills

Binary, octal, denary and hexadecimal. Four different ways of representing numbers, all perfectly logical once you know what you are doing — and remarkably good at making you question whether you actually know what you are doing when somebody puts you on the spot.

So, rather than simply reading about number systems, it is time to put that knowledge to the test.

Welcome to the Number Conversion Challenge, a simple game designed to test how quickly and accurately you can move between BIN, OCT, DEN and HEX.

Number Conversion Challenge. JUMP TO PLAY

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🧮 Four Number Systems, One Challenge

Computers might ultimately deal in ones and zeroes, but binary is only one of the number systems you will encounter when working with computing and digital technology.

The Number Conversion Challenge uses four:

Binary (BIN) is base 2, using only 0 and 1.

Octal (OCT) is base 8, using the digits 0 through 7.

Denary (DEN) — also commonly called decimal — is base 10, the everyday number system using 0 through 9.

Hexadecimal (HEX) is base 16, using 0 through 9 followed by A through F.

Knowing what each system is, however, is the easy bit. The real challenge begins when you have to convert between them.

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🎯 The Number Conversion Challenge

The game randomly chooses two different number systems and gives you a value to convert.

You might be given:

DEN → BIN

Perhaps the next question will be:

HEX → OCT

Or just when you have settled into converting everything back to denary:

BIN → HEX

There are twelve possible conversion directions covering every combination of BIN, OCT, DEN and HEX.

Enter your answer and the game immediately checks whether you got it right. Correct answers earn points, consecutive correct answers build your streak, and getting one wrong resets that streak.

Simple enough.

Until hexadecimal letters start appearing.

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🎮 Play the Game

Enough theory. Here is the important bit.

See how many conversions you can get right and, more importantly, how long you can keep your streak going.

The current challenge uses values from 1 to 255, making it useful for practising the sort of conversions commonly encountered when learning computer science and digital number systems.

There is no need to add prefixes such as 0b or 0x, although the game will understand them if you do.

Just enter the converted value and see whether you were right.

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🔢 BIN – Binary

Binary is the language sitting underneath virtually everything a computer does.

Unlike our normal base-10 system, binary has only two possible digits: 0 and 1. Each position represents a power of two.

For example:

13 in denary = 1101 in binary

That is:

8 + 4 + 0 + 1 = 13

Binary values can become rather long compared with their denary equivalents, but once the powers of two become familiar, converting smaller values starts becoming surprisingly quick.

The question is whether you can still do it when the game suddenly throws 11010110 at you.

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🧠 OCT – Octal

Octal uses base 8, meaning each digit can range from 0 to 7.

It might not appear quite as frequently as binary, denary or hexadecimal in everyday computing discussions, but it is still an important number system — and adding it makes the conversion challenge considerably more interesting.

For example:

64 in denary = 100 in octal

Octal also has a useful relationship with binary because each octal digit corresponds neatly to three binary bits.

That means once you understand the relationship between the two, BIN ↔ OCT conversions can sometimes be solved without going through denary at all.

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⚙️ DEN – Denary

Denary is home territory.

It is the base-10 number system most of us have used since we first learned to count, with ten possible digits from 0 to 9.

That familiarity makes converting into denary a useful way of understanding what a binary, octal or hexadecimal value actually represents.

The challenge comes when you have to go the other way.

Being shown 173 and asked for its hexadecimal equivalent requires a rather different thought process from simply recognising the number one hundred and seventy-three.

And, naturally, the game is perfectly happy to change which direction you are travelling with every question.

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💻 HEX – Hexadecimal

Hexadecimal is base 16, which creates an interesting problem: our normal numerical digits run out at nine.

The solution is to borrow some letters.

After 9, hexadecimal continues with:

A = 10
B = 11
C = 12
D = 13
E = 14
F = 15

So:

255 in denary = FF in hexadecimal

Hexadecimal is particularly useful in computing because one hexadecimal digit represents exactly four binary bits. A long binary value can therefore be represented much more compactly in HEX.

It also means BIN ↔ HEX is another conversion where recognising the relationship between the two systems can save quite a bit of work.

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🏆 Chase the Streak

The scoring system rewards getting several questions correct in succession.

A correct answer starts at 10 points, with additional points awarded as your streak increases. Make a mistake and you do not lose your existing score, but your streak returns to zero.

That makes the objective slightly more interesting than simply answering isolated questions.

Can you get five in a row?

Ten?

Can you reach the point where BIN, OCT, DEN and HEX stop looking like four different systems and you simply recognise the relationships between them?

There is only one way to find out.

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🔧 Built for Practice

The Number Conversion Challenge is deliberately straightforward.

There are no lengthy tutorials standing between you and the questions. You are given a number, told what it currently represents and what you need to turn it into.

Then you have a go.

If the answer is wrong, the game shows you the correct value. If you accidentally enter something impossible — such as an 8 in an octal answer or a 2 in binary — it will tell you that too rather than simply marking it incorrect.

That makes it useful both as a quick challenge and as a practice tool if you are currently learning number systems.

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🚀 Where Could It Go Next?

This is the first version of the Number Conversion Challenge, but there is plenty of room to make things more difficult.

Larger numbers, selectable difficulty levels, timed challenges, limited lives, multiple-choice rounds and dedicated modes for particular conversions could all turn a simple practice tool into something considerably more dangerous to your free time.

For now, though, there are four systems and twelve possible conversion directions waiting for you.

BIN. OCT. DEN. HEX.

How high can you get the score before one of them catches you out?

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🌐 More from Dr Ravenholm

This is just one of the things happening around the slightly strange collection of gaming, technology, projects and general experimentation that makes up Dr Ravenholm.

You can explore more on the Transparent Aluminium blog or have a look around the main Transparent Aluminium website.

For the gaming side of things, you can also find me on YouTube and join the livestreams over on Twitch.

If you want to become part of the community, join us on Discord, where you can usually find somebody willing to discuss games, technology, questionable ideas and whatever else we have managed to get ourselves involved with.

Until next time,

Dr Ravenholm