Numbers

12345678
Across
  1. 3. A group of ten hundreds
  2. 4. The number that represents the absence of any quantity
  3. 6. The sum of the first three prime numbers
  4. 7. The second and smallest even prime number
  5. 8. A group of ten tens
Down
  1. 1. A group of one thousand thousands
  2. 2. The smallest odd prime number
  3. 5. The first and smallest positive integer
  4. 6. The smallest composite number
  5. 7. The base unit in the decimal number system