You will want to start off by converting the fractions to mixed numbers.
starting with 25/3, I like to just divide and convert the decimal, if it has one, to a fraction, so
25/3 = 8.333
0.333 = 1/3
therefor, 25/3 = 8 1/3
then do 42/3
42/3 = 14
now that we have this we can plot them on the number line.
looking at the number line, it starts at 5 and goes to 15, then if we count the larger dashes we will see that it counts by 1's. These larger marks are then split into thirds by two smaller dashes. using this information you should be able to plot these numbers.
Starting with 8 1/3
count from 5 up to 8 with the larger dashes.
once you get to the dash for 8, count one small dash between the larger 8 dash and the 9 dash. This is where you should plot 8 1/3, make sure to label it as well.
Now for 14
this one is simple. count the larger dashes from 5 up to 14, then you can plot 14.
your number line should look like the attached image :)