School Crossword puzzle

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Across
  1. 3. Someone who teaches
  2. 4. a machine that can solve simple equations like multiplication, addition, subtraction and division
  3. 6. a book with all the words
Down
  1. 1. The study of shapes
  2. 2. a book with every topic in a subject
  3. 4. A room where someone teaches
  4. 5. assignments to do at home