Explanation:
the mode is the data item that occurres the most often.
but in 4, 5, 0, 2, 3, 1 every number appears only once. so, the mode is 0, 1, 2, 3, 4, 5 (as special case this average number can have more than one value - like in our case here).
the median is the value in the data set that lies directly in the middle between the other values (half of them are higher, the other half is lower).
if our data set has an even number of data points, or there is no unique middle value for other reasons, then the median is the mean value of the 2 middle values.
in our case 2 and 3 are the 2 middle values, so the median is (2+3)/2 = 2.5
the mean value is directly the average value across the whole data set : the sum of all values divided by the number of values.
(0+1+2+3+4+5)/6 = 15/6 = 2.5
the range is the difference between the highest and the lowest value in the data set : 5 - 0 = 0