Diagrams, charts and graphs
Diagrams, charts and graphs

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Diagrams, charts and graphs

3.3 Decimal and fraction coordinates

Where necessary, the coordinates of a point can be specified by using decimals or fractions. However, locating points whose coordinates are not whole numbers requires more precision when reading along the axes. For example, here the coordinates of the point A are (2.2, 1.8).

A point P with coordinates (0.32, 0.24) would be particularly difficult to plot accurately on the axes above because of the scales used. You can only plot the point approximately. But, if a larger scale were used for the axes, it would be quite easy to plot P with reasonable accuracy, as shown below.

Similarly, to plot points with very large coordinates, such as a point Q with coordinates (3020, −1450), a very different scale would be needed.

Notice that, even using scales like these, it is impossible to plot points such as Q exactly.

Mathematical coordinate grids are used for maps, plans, geometric diagrams and also for graphs. For the first three of these, the scales on the axes of the grid must be the same (otherwise shapes would be distorted and diagonal distances would be incorrect). For graphs, the scales on the axes need not be the same – in fact, often the two scales represent very different things.


Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371