The Distribution of digits in numbers chosen at random from the telephone directory are:

Digit 0 1 2 3 4 5 6 7 8 9

Frequency 1026 1107 997 966 1075 933 1107 972 964 853

Test whether the digits may be taken to occur equally frequently in the directory

My problem is which test to chose and why? Though I think that I should use Chi-square test, I still can't confidently say why? If it is chi-square test, then I don't know how to calculate expected frequency, Is there any specific formula to calculate it?