URGENT! how to create a chart? Nothing is clear to me!

Need help Plugins
1

CHART

I’m creating a PIE chart.

it has two colors(parts)
one is sum of number a,b,c .
and the other is 500- (a+b+c)

how can I create it?
what is value expression and label expression?

I would appreciate a lot if you can teach me…!

THanks,

It’s not solved… with free plugin, how do we use it??

2

Try this out.

3

thanks but how about with free chart plugin??

4

Read this:

You need to use “group by”