7th Grade · The Number System
Repeating Decimal
7.NS.A.2d
Definition
A decimal in which a digit or group of digits repeats infinitely, shown with a bar (vinculum) over the repeating part.
Examples
- 0.333... is written 0.3 with a bar — the 3 repeats.
- 0.142857142857... is written with a bar over 142857 — the 6-digit block repeats.
Key rule
Write a repeating decimal with a bar instead of '...' to show the pattern.
Memory hook
The bar means it repeats forever.