Image Credit

Description:

A happy face with underneath the word 'happy' next to an orange bar that shows the indication 100%. A sad face with underneath an orange bar next to the word 'happy'. The bar is about 2/3 dark; 59% is written in the bar. A second, red, bar with the word 'sad' written next to it is about 1/3 dark and displays 41%.

Source:

Sabine De Brabandere, Science Buddies

License:

Science Buddies