Paint a column in a building. To calculate the area to be painted is to calculate the bottom area of the column

Paint a column in a building. To calculate the area to be painted is to calculate the bottom area of the column

Of course it's wrong. I'm in grade six!

There are 8 cylindrical columns in the school corridor. The bottom radius of each column is 4 decimeters and the height is 30 decimeters. Now, if you want to paint these columns, if you use 0.25 kg of paint per square decimeter, how many kg of paint do you need?

2 × 3.14 × 4 × 30 × 8 × 0.25 = 6.28 × 4 × 30 × 8 × 0.25 = 25.12 × 30 × 8 × 0.25 = 753.6 × 8 × 0.25 = 6028.8 × 0.25 = 1507.2 (kg) a: a total of 1507.2 kg of paint is required

There are 8 cylindrical columns in the school. The diameter of the bottom of each column is 4 decimeters and the height is 30 decimeters. Now we need to paint these columns, if we need to paint every square meter
25 kg. How many kg of paint are needed?

3.14×4×30×8
=3014.4 square decimeters
=30.144 square meters
30.144 × 0.25 = 7.536kg