Fantastic special numbers

1234567
Across
  1. 1. 50÷10=5, the math terminology for 10
  2. 4. 5*4=20, the math terminology for 4
  3. 5. 5*4=20, the math terminology for 5
  4. 7. 6-2=4, the math terminology for 6
Down
  1. 2. 6-2=4, the math terminology for 2
  2. 3. 50÷10=5， the math terminology for 50
  3. 6. 1+2=3, the math terminology for 1 or 2