Mammoth Memory

Notation for recurring decimals

Sometimes when you divide into a number there is a recurring decimal

Because a third has an infinite amount of 0.3's it is a recurring decimal

13=0.333333.......recurring

This can be written as

 13=0..3
or
13=0.ˉ3

The dot or dash means that the 3 is repeated indefinitely.

But repeated decimals can occur in a pattern.

If 2 recurring symbols are shown, it means the numbers between the symbols are repeated

This can be written as

 47=0..5714.2   or  47=0.ˉ5714ˉ2

This is written with a dot over the first and last part of the recurring pattern.

 

Example 1

Put the following fraction in recurring decimal form 227

 

If 2 recurring symbols are shown, it means the numbers between the symbols are repeated

 

Written out recurring decimal

   

Example 2

What does 1..5 mean?

1..5 means 1.5555555 repeating

 

Example 3

Write 22.520101010 as a recurring decimal using dots

This equals 22.520.1.0

 

Example 4

Express 49 as a decimal

0.4444 can also be a recurring decimal but make sure it has the dot or dash above the repeated number

 

49=0.4444 recurring

49=0..4