First, draw the number line and assign the values of the real numbers that correspond (See the figure attached).
Now, let's represent the mixed numbers given in the problem.
Let's start with 8 2/5: This mixed number is located between 8 and 9. The numerator 2 of the fractional part, tells us how far from 8 it will be located and the denominator 5 indicates how many parts we must divide the space between these two numbers (8 and 9).
Now, to plot 2 3/4 on the number line, we have to follow the same proccedure: It is located between the numbers 2 and 3. The numerator 3 of the fractional part, tells us how far from 2 it will be located and the denominator 4 indicates how many parts we must divide the space between 2 and 3.