28. a) use a ruler to make a number line between 0 and 1 that includes all the
tenths (1.e., from 0.1 up to 0.9), and includes 0.25, 0.5, and 0.75. (you may
want to start by making a mark on your number line at every inch from 0 to
10. the first mark would be zero and the last would be 1, and the numbers
in between would be the tenths.) b) do the same thing to make a
number line between 2 and 3 and include the tenths from 2.1 to 2.9, as well
as 2.25, 2.5, and 2.75.