1/2 - a half
1/3 - a / one third
3/4 - three quarters
2/9 - two ninths
0.25 - zero / nought point two five
2.456 - two point four five six
7.089 - seven point o[ou] eight nine
. 7 - point seven

Note!
простая дробь - vulgar fraction
десятичная дробь - decimal (fraction)
правильная [неправильная] дробь - proper [improper] fraction
непрерывная дробь - continued fraction