If you need to replace the phrase "does the top of your head," there are several synonyms you can use. For example, "off the top of my head" is a commonly used phrase that means the same thing. Some other alternatives include "from memory," "without looking it up," "without thinking too hard," or "immediately." These phrases all convey a similar casual and spontaneous tone. Alternatively, you might consider using a more formal phrase, like "consequently" or "henceforth". Regardless of which phrase you choose, the key is to express yourself with precision and clarity.