1, surface area of cylinder = lateral area of cylinder+bottom area× 2, that is, S table =S side +S bottom× 2 or 2πr×h+2×π.

2. A cone has only one bottom surface, and the bottom surface is a circle. The side of a cone is a curved surface.

3. Fractional multiplication: The significance of fractional multiplication is the same as integer multiplication, and it is a simple operation to find the sum of several identical addends.

4. Reciprocal: Two numbers whose product is 1 are called reciprocal.

5. Application problem of fractional division: first find the unit 1. Known unit 1. Multiplication is used to find partial quantity or corresponding fraction, and division is used to find unit 1.