destini's crossword puzzle

1234567
Across
  1. 3. 1step sometimes 2/has letters and numbers
  2. 6. a symbol
  3. 7. an object that has
Down
  1. 1. the amount of the inside of something
  2. 2. the number of cubic units in an object
  3. 4. a problem
  4. 5. a endless number