Final answer:
The stage manager notates blocking in a prompt book for technicians, record-keeping, and because actors do not write it down.
Step-by-step explanation:
The stage manager notates blocking in a prompt book for several reasons. First, it is important for technicians who need to know where the actors move on stage so they can set up the appropriate technical elements like lighting and sound cues. Second, notating blocking provides a record of the last movement decided on for every moment of the production, ensuring consistency throughout. Lastly, actors do not write the blocking down, so the stage manager takes on the responsibility of documenting it in the prompt book.
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