To convert a percent to a decimal, you move the the decimal left two places to convert the percent to a decimal. For example, if you were to convert 14% to a decimal, you move the decimal left two places so that 14% converted to a decimal would look something like this: 0.14
First work out the number of shelves per bookcase: 65/13 = 5 It is 5 shelves per bookcase. 6 x 5 = 30. Therefore 32 shelves are enough to make 6 bookcases.