1 .50 cents a trip. 2. Two sheep fight. 3. It's completely cost-effective. 4. Always count money.

5. Both sides count. Everything will be fine. All shall be well, jack shall have Jill. Legal fees. Beat each other.

9. Fishing 10. Equestrian 1 1. Yi 12. Chongyang is now Chongyang.

13. Tracing back to the source 14. Prescription 15. Dove 16. Collective fishing

17. Divorce by agreement 18. Painting 19. Team competition 20. Shave.

2 1. Who will escort Lin to Cangzhou?

Second, riddles with numbers as riddles

23. one (playing an idiom) 24. One hundred thousand (to use an idiom)

25. One, two, three, four, five, six, seven, nine (with ancient book names) 26.

27.3824 (playing a sports term) 28.7 × 9 (playing an ancient rank, scrolling)

Third, riddles with equations as riddles

29.X = only-I (industrial term) 30. X = Xu ÷3 (chemical term)

Fourth, riddles with mathematicians as the answers.

3 1. Dongpo Youchun 32. If she just turns her head and smiles, there are a hundred spells.

5. Riddles with mathematical subjects as riddles

33. Analytic geometry (in oral language)

6. Riddles with operation symbols as riddles

34.+-× (Idiom)

Answer:

1. One-dimensional quadratic (extrapolation algorithm) 2. Relative vertex angle 3. Absolute value 4. Constant (pass-false method) 5. Score 6. Concentric circle 7. Rational number 8. Common ground 9. Equal to (pass-false method) 10. Multiplication 1 1. Internal angle (0. Pass) 16. Ordinary vertical line 17. Approximate score 18. Square angle 19. Right angle 20. Square angle (part of speech) 2 1. Equal angle 22 degrees. Two solutions and differences (question and answer method. Answer. Separating device) 23. Many people are infallible (otherwise there would be no "one" and "ten thousand") 25. Mouth (the riddle means "only" and "less than eight") 26. Take a note (meaning forget to write "take a note") 27. Women's doubles (doubles is two dozen, 24)) 34. Fragmentation (dividing branches into "+,-,×")