The idiom to count the number of something on one hand emphasises that this does not happen very often, or that there's a small number of something – after all, you can only count to five on one hand!
习语to count the number of something on one hand强调这种情况并不经常发生,或者某物数量很少。毕竟,你一只手只能数五!
I want you to take a deep belly-breath through your nose for five seconds hold it for a second, then push all the air out through your nose, slowly, counting to five.