Meaning & use
decimal expansion
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Meaning
nouncountablemathematics
The way a number is written as digits after a decimal point, either stopping or repeating forever.
Grammar: Countable: you can say a decimal expansion, the decimal expansion of 1/4, etc.
Patterns
- the decimal expansion of a number
- a terminating decimal expansion
- a repeating decimal expansion
The decimal expansion of 1/4 is 0.25, which stops after two digits.
The decimal expansion of 1/3 is 0.333... and goes on forever.
Students learn to find the decimal expansion of fractions using long division.
Word forms
| plural | decimal expansions |
|---|
Common combinations
- terminating decimal expansion
- A terminating decimal expansion has a finite number of digits after the point.
- repeating decimal expansion
- A repeating decimal expansion shows a pattern that continues indefinitely.
- decimal expansion of a fraction
- You can find the decimal expansion of a fraction by dividing the numerator by the denominator.
- infinite decimal expansion
- An infinite decimal expansion never ends, like the one for pi.
Synonyms and how they differ
- decimal representation
- A broader term that can also include the digits before the decimal point, not just the part after it.
Word family
Commonly confused: decimal expansion or decimal point?
decimal expansion vs decimal point
A decimal point is just the dot itself, while a decimal expansion refers to all the digits that come after it.
Practice
Which sentence uses 'decimal expansion' correctly?
Choose one answer.
0.4 is the correct decimal form, and it terminates. Option 2 is a fraction, not a decimal. Option 3 wrongly says it repeats. Option 4 gives the reciprocal.
Make it your own
Write a sentence using “decimal expansion”, then check it and compare it with the examples above.