Subtraction within 20

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Across
  1. 3. 18-3=
  2. 6. 19-8=
  3. 7. 16-12=
  4. 9. 20-2=
Down
  1. 1. 16-7=
  2. 2. 17-7=
  3. 4. 18-6=
  4. 5. 19-12=
  5. 7. 16-11=
  6. 8. 10-2=