Terminating Decimal Constraint
GMAT glossary · Playbook
Definition
A reduced fraction a/b has a terminating decimal if and only if every prime factor of b is 2 or 5 (b = 2^x · 5^y).
Terminating Decimal Constraint in plain English
Pull Terminating Decimal Constraint when ask whether a fraction in lowest terms has a terminating decimal. Clues include Terminating decimal, finite decimal, lowest terms. Blueprint: Reduce a/b. It terminates iff every prime factor of b is 2 or 5, so b=2^x· 5^y. Why it beats the long way: Long division is slow. The prime test on the denominator settles it in one check. Micro-example: 7/20 and 3/16 terminate because 20=2^2· 5 and 16=2^4. 1/6 does not, because after reducing, the denominator still has a factor 3.
Sign up free: all 257 GMAT terms as flashcards, plus practice questions with full explanations →
Related GMAT terms
GMAT practice questions · GMAT flashcards · GMAT study guide