"Have someone's number" is a common phrase that means to understand someone's true character or motives. However, there are several synonyms that can be used in place of this phrase. One such synonym is "see through someone", which suggests that the person's deception or manipulation is transparent and easily recognizable. Another synonym is "know someone's game", which implies that the person has a specific strategy or plan that is easily discernible. Additionally, "have someone's measure" is a British term that means to have a good understanding of someone's abilities or limitations. All of these synonyms convey the idea of being able to see through someone's façade and understand their true intentions.
