number system

12345678910
Across
  1. 5. represented by the letter Z
  2. 6. 8/9
  3. 8. denoted by R
  4. 9. pie day
  5. 10. least whole number
Down
  1. 1. applied for right angle
  2. 2. non-negative counting numbers
  3. 3. cannot be represented by ratio
  4. 4. 0.99999999....
  5. 7. there are ____ rational numbers between two rational numbers.