math

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Across
  1. 2. A number that has no number of its own?
  2. 5. The initial title of zero?
  3. 6. what is the name of a figure with 6 corners
  4. 7. How many walls does a cube have?
  5. 8. What is a mathematical "recipe" for doing something?
  6. 9. What is the circumference of a circle also called?
Down
  1. 1. Who discovered zero (0)?
  2. 3. What unit is a hundredth of a meter?
  3. 4. What is before the Quadrillion?
  4. 5. what was the first country to use negative numbers?