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TechKnowSurge Catalog Interactives Which Number System?
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Which Number System?

Sort each job into the number system that fits it: decimal, binary, hexadecimal or octal.

⚑ Complete this interactive to capture a CTF flag worth 5 points.

About this interactive

Computers store everything as bits, but people write those values in four systems, each for a reason. Decimal is what we use every day, so it is the easiest to read: an IPv4 address is far easier to say in decimal than as a long run of 1s and 0s. Binary is needed when the bits themselves matter. Subnetting a range means getting down into the individual bits. Hexadecimal converts easily to and from binary. Split a byte into two nibbles of four bits, and each nibble becomes one hex digit. That is why IPv6 addresses are written in hex. Octal is used for Unix and Linux file permissions: read, write and execute for the user, the group and everyone else. Nine flag bits do not split evenly into nibbles, but each group of three adds up (4 + 2 + 1) to one digit from 0 to 7, so 750 gives the user read, write and execute, the group read and execute, and everyone else nothing. Drag each job to the system that fits it.

What you'll learn

Aligned to

CompTIA Tech+
1.1 Compare and contrast notational systems.

Key terms

Decimal
The base-10 number system using digits 0–9; the standard system used in everyday counting and arithmetic, and the most common format for presenting numeric output to humans.
Binary
The base-2 number system that uses only the digits 0 and 1; the native language of digital computers, which store and process data as electrical on/off states.
Hexadecimal
Hex
A base-16 number system using digits 0–9 and letters A–F; each hex digit maps to exactly 4 bits, making it a compact shorthand for representing binary data.
Octal
A base-8 number system using digits 0 through 7, where each digit represents exactly three binary bits; commonly used in Unix and Linux file permission notation because a three-bit permission group (read, write, execute) maps cleanly to a single octal digit.
Nibble
A group of exactly 4 bits, equivalent to one hexadecimal digit; two nibbles make up one byte.

Topics

Number Systems Binary Decimal Hexadecimal Octal Interactive Categorize

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