In Hogwarts Legacy there are many locked doors inside the archways decorated with 10 icons of magical and mythical creatures, and opening these doors requires solving math puzzles which can be a bit confusing at first. Several of these puzzle doors are located in the annex section of the Hogwarts School of Witchcraft and Wizardry Library, including one near the Floo Flame in the Divination Classroom, which sits above the central hall of the library annex.
Related: How to Complete the Charms Classroom Door Puzzle in Hogwarts Legacy
How to Open the Divination Class Puzzle Door in the Library Annex
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The puzzle door isn’t inside the Divination classroom itself, but it’s very close to the Divination classroom Floo Llama, so get there quickly or set it as a waypoint and walk there. From Divination Floo Flame, head northwest, then turn left, then right, and you’ll find the puzzle door surrounded by blackboards and stacks of books.
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To unlock the door you must roll the symbols on the triangles on both sides of the door so that the numbers at the points of the triangles add up to the numbers inside the triangles. The symbols around the door correspond to the numbers 0 to 9, from left to right. So the top triangle says 2 + 3 +? = 9, which means the missing number must be 4, which is represented by the owl icon (at least it’s supposed to look like an owl). Roll the triangle to the left until it shows an owl.
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The lower triangle indicates 0 + 1 + ?? = 4, so the missing number must be 3, which is represented by the hydra icon. So rotate the triangle to the right until it shows a hydra. You should now be able to open the door and reach the Arithmancy classroom beyond. You can also find the Arithmancy Classroom Field Guide Page and the Telescope Conjuring Exploration collectible beyond this door.
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