To do this you need each of the numbers to be either a mixed number or a number with a decimal. Since two of the numbers have decimals, it would be easier to change the on with the fraction.
To change a fraction to a decimal you have to to divide the two numbers. 4/5=.8
Now you have the three numbers of 2.3, 2.8, and 2.6.
Now put them in order. Since all of the numbers have 2 in the ones place you have to use the tenths place to determine what is the smallest. 3 is the smallest number and 8 is the biggest.
These are the numbers in order:
2.3, 2.6, 2 4/5.