have no idea of how things stand; not know the true state of affairs;not sure of (oneself)
❍ 一切都是胸中无“数”，结果就不能不犯错误。(《毛泽东选集》1380) They have no“figures”in their heads and as a result cannot help making mistakes.
胸中无数xiōnɡ zhōnɡ wú shù
比喻对情况不了解，心里没有底。not to know what’s what, not know for certain, feel unsure of sth.