5/9 is an amount that cannot be exactly represented in the decimal system because 9 will not go into 10 evenly.
There is a trick you can use to indicate the correct value directly. Start to write the number, but after the decimal write the repeating portion only once - then draw a bar over the repeating portion. This indicates the full answer more specifically than the more common use of 0.555...
repeating decimal
A repeating decimal is usually shown with a bar over the decimal that is repeated
29/7 as a repeating decimal is 4.'142857' repeating '142857'
0.3333 repeating
It is: 5.'63' repeating '63'
Either, the decimal with a line over what's repeating (eg. 0.6 with a line over it), or decimal repeating (eg. "point six repeating").
The line over a repeating decimal is called the vinculum.
repeating decimal
7 over 12 as a repeating decimal = 0.583333...
It is placed over one length of repeating decimal digits.
A repeating decimal is usually shown with a bar over the decimal that is repeated
2 over 11 written as a repeating decimal = 0.18181818...
For a single repeating digit, it is a dot over the digit.For string of repeating digits, it can be a dot over the first and last repeating digits, or a bar over the repeating string.
29/7 as a repeating decimal is 4.'142857' repeating '142857'
0.173333 repeating
0.4444 repeating
0.3333 repeating