Foundational math vocabulary
Digit
Pronunciation: DIJ-it
A digit is one of the symbols used to write numbers. In base ten, the digits are 0 through 9.
0–9Foundational
Plain language
What it means
A digit is one of the symbols used to write numbers. In base ten, the digits are 0 through 9.
Formal meaning
Mathematical definition
A digit is a single symbol in a positional numeral system; its value depends on both the symbol and its place.
Where it fits
Its place in mathematics
Digits are the building blocks used to record whole numbers, decimals, codes, and measurements.
Why it matters
The practical reason to learn it
Understanding digits prevents place-value errors and makes large numbers easier to read and compare.
Worked example
Find the value of a digit
What value does the digit 7 have in 47,206?
- Locate the 7 in the thousands place.
- Multiply 7 by 1,000.
The digit 7 has a value of 7,000.
Real-life example
Where this appears
A programmer reads individual binary digits when inspecting low-level data.
Common mistake
What to watch for
Calling 47,206 a five-digit value and then saying each digit has the same size. Position changes value.
Memory tip
Keep this in mind
Name the place after the digit: seven thousands, not merely seven.
Little-known fact
Keep curiosity alive
A digit can be used as a label, such as a jersey number, without representing a quantity.
A profession that uses this idea
Data begins with symbols
Programmers work with decimal digits, binary digits, hexadecimal symbols, and coded identifiers.
Explore Programmers & Data AnalystsFollow the learning trail
Prerequisites, related ideas and next concepts
People behind the ideas
Related Math Heroes
Aryabhata
Aryabhata was mathematician and astronomer. He wrote compact rules for arithmetic, algebra, trigonometry, astronomical calculation, and an approximation to pi.
Al-Khwarizmi
A scholar whose systematic writing on calculation and equation solving helped shape algebra and whose name became the root of the word algorithm.
Put the idea to work