Real Math Errors!

Here have been several instances where companies and advertisers have "got the math wrong."
Below are some prime examples of where the math went wrong:

 I'm not sure about "how much you save?"

Image taken by JPostman

What is wrong with this advertisement?

Image taken by Kelly Ruley

How many chicken nuggets do we get?

image found at Imgur

Is the cereal below showing the correct math for the percentage more? Did the advertisers get this one right or wrong? What do you think? Comment with your solutions below.

 

Cheers,