observed expected (obs.-exp.)^2 (obs.-exp.)^2/expected
men 8 10 4 4/10
women 14 10 16 16/10
children 8 10 4 4/10
chi-square = 24/10 = 2.4
degrees of freedom = 3 -1 = 2
Under the null hypothesis, the chance that chi-square 2.4 is, by the table, about 30%, which is accordingly the right choice.