Plotting positive and negative data onto a graph

Yesterday we looked at the difference between the hottest and coldest temperatures of many cities from around the world.

We found that sometimes the coldest temperature was below zero and to calculate the range it helped to think of a number line.

If the coldest temp was minus 12 degrees and the hottest temp was positive 28 degrees then the difference between these two temperatures would be 40 degrees.

Today we will create graphs to show how the temperature changes over a year.

Click here to visit the weatherbase website again.  Find a city from anywhere in the world but make sure that the temperature goes below freezing (0 degrees) at some point in the year.

Now draw a chart.  The x-axis will be labelled with the months of the year and the y-axis will have the temperature.  Make sure your y-axis lets you go below 0.

1) Plot each point accurately in your book.  Use a coloured pencil to join the dots.
2) Plot a second city using a different colour.  For an interesting comparison, choose 1 city from the Northern Hemisphere and 1 from the Southern Hemisphere.

Your finished graph should look something like this...

The above graph was made using this website.  Try it out for yourself and download a finished graph as a picture.  You can also use Excel if you have it installed on your computer.