Introducing Simple Equations

The scale you see below was loaded with a certain number of red packets on the left tray. Try to balance the scale by loading blue packets on the right scale using the blue slider to increase their number. Once you find out how many blue packets you need you may request a new challenge by clicking the button in the upper left corner.
Solve a few problems and note how many blue packets you need for different numbers of red packets. How many blue packets do you need to balance a single red packet?