How to write repeating decimals with a bar
Some decimals end, and others go on forever. If a group of digits keeps repeating, we can write the group once and put a bar over it. The bar tells us exactly where the repeat starts.
Separate the part that repeats from the part that comes first
The decimal terminates because it has a last digit. In , the digits come first and then the digit repeats forever. Put the bar over just the .
A decimal can also go on forever without an eventually repeating pattern. For example, starts and has no repeating group to mark with a bar.
Put the bar over a group of two digits
In , we see followed by again. The pattern starts right after the decimal point, so the bar goes over both digits.
A zero can be part of the group too. In , the repeating group is , so keep both digits under the bar.