by the numbers源自20世纪初西方军事训练与音乐演奏场景——军队操练时士兵按数字指令行动，乐队演奏时按编号乐谱机械执行，后引申为通用表达。核心语义有二：
1. 字面义“按数字、依编号”；（此时the可以省略）
Identified only by numbers, the custodial droids are a nice touch.
这些保洁机器人仅按编号标识，设计十分巧妙。
Go by the numbers and send each letter certified.
按编号处理，每封信都要寄挂号件。
To ensure accuracy, she followed the recipe by the numbers, measuring each ingredient precisely.
为保证精准，她严格按食谱上的数值操作，精确称量每种食材。
2. 引申义“机械地、按部就班地、缺乏创意地、循规蹈矩、严格遵循规则，按固定模式行事，按照标准来；一板一眼”（高频考点），侧重行动遵循固定流程，无灵活发挥或真情实感。
如：
The recruits followed the drill by the numbers.新兵们按部就班地进行操练。
She completed the report by the numbers, without adding any original ideas.
她机械地完成了报告，未加入任何原创观点。
Their marriage was just going by the numbers—no passion, just routine.
他们的婚姻只是按部就班地维系着，没有激情，只剩例行公事。The diplomat handled the negotiation by the numbers, sticking to the official agenda.
外交官严格按官方议程机械地处理了谈判。
He asked her out not because he liked her, but by the numbers—everyone said they should date.
他约她出去不是因为喜欢，只是随大流按部就班——大家都说他们该约会。
The government’s economic policy was implemented by the numbers, failing to address real issues.
政府的经济政策机械推行，未能解决实际问题。
Their dating life was so by the numbers—dinner, movie, goodnight kiss, no surprises.
他们的约会生活毫无新意，总是晚餐、看电影、晚安吻，毫无惊喜。
The teacher taught math by the numbers, making students memorize formulas instead of understanding them.
这位老师教数学机械死板，让学生死记公式而非理解原理。
Politicians who play by the numbers rarely make history.
机械行事的政客鲜有机会创造历史。《纸牌屋》
Many young people now approach relationships by the numbers, following social media’s 'rules' for dating instead of being true to themselves.
许多年轻人现在循规蹈矩地处理关系，遵循社交媒体的约会“规则”，而不是忠于自己。（ 2023年高考英语新课标I卷）
