2. denominator.

3. Proportion.

4. Divide it.

5. Fake scores.

6, the center of the circle.

Second, 1 remains unchanged.

2. Hang upside down.

3, seven ups and downs

4, no three no four.

Third, 1, fat.

2, crystal.

Step 3: One day

4. cypress

5. One hundred

Fourth, 1, Zu Chongzhi

2. Yang Le

3. Chen Jingrun