Yes, you need to make a scale.
For example suppose all the numbers you need to graph are given to one decimal place.
Then make 10 of the smallest blocks on your graph = 1 so that each small block = 0.
If you have a graphing calculator, try graphing some equations with large numbers and see what the calculator does. Just graph y = x2 and look at the numbers on the x and y axis. Find the point (1,1) and then look at the points to the left and figure out what they mean.
Another example: look at a map and see the scale where you'll find something like 1" = 50 miles. You can do the same thing with a graph.
I hope that helps.