The SSAT writing section is a required part of the exam, lasting for 25 minutes. However, it is not scored. So why do you need to write? Because your essay will be sent along with your scores to the admissions office of the schools you're applying to. The teachers there will evaluate your ability to express your thoughts through your writing, especially how you present and argue for your point of view. The schools you apply to will certainly review your essay carefully, so everyone should take the writing section very seriously.