The answer in the sixth grade mathematics textbook of Beijing Normal University is 1 1- 12.

Practice the answer to question 1 on page 12.

The volume of the cone and the third

These two cylinders have equal volumes. Because the volume of the cone is equal to 1/3 of the volume of the cylinder with the same height as its bottom surface, in the figure, the cone is the same as the bottom surface of the third cylinder, and the height of the third cylinder is 1/3 of the cone height, so their volumes are equal.

Practice the answer to the second question.

Left: 1/3

×9×3.6= 10.8 (m3)

Chinese numerals:1/3× 3.14× 32× 8 = 75.36 (dm3)

Right:1/3× 3.14× (8 ÷ 2) 2×12 = 200.96 (cm3).

Practice the answer to the third question on page 12.

1/3×3. 14×(5÷2)2×4≈26. 17(cm3)

12 page Practice the answer to the fourth question.

(1) 3.14× (5 ÷ 2) 2 =19.625 (square meter)

(2)1/3×19.625× 3.6 = 23.55 (m3)

Practice the answer to the fifth question.

9.42÷3. 14÷2= 1.5 (m)