a/one hundred, a/one hundred and one, a/one hundred and thirty-eight, five hundred and seventy-two, a/one thousand, thirty-six thousand four hundred and twenty-nine, a/one million.

In British English and comes between the hundreds and the rest of the number, e.g. five hundred and seventy-two. But Americans say five hundred seventy-two without and.

8:00 a.m. 10:00 p.m. We use a.m. (before noon) and p.m. (after noon) or in the morning/in the afternoon/in the evening/at night to make clear which part of the day we mean.

half past seven/seven thirty. half seven (informal)