80,000 blondes meet at the Wembley Stadium for a "Blondes Are Not Stupid" convention. 

The master of ceremonies says, "We are all here today to prove to the world that blondes are not stupid. 

Can I have a volunteer?" One blonde steps up, so the master of ceremonies asks her, "What is 15 plus 15?" After 15 or 20 seconds, she replies, "Eighteen." Obviously everyone is a little disappointed. 

Then 80,000 blondes start chanting, "Give her another chance, give her another chance." 

The master of ceremonies says, "Well, since we've gone to the trouble of getting 80,000 of you here and the World Wide Press, I guess we can give her another chance." So, asks her, "What is 5 plus 5?" 

After 15 or 20 seconds, she replies, "Ninety." The master of ceremonies sighs. Everyone is crestfallen and the blonde starts crying. Again, the 80,000 girls start chanting, "Give her another chance, give her another chance." Unsure whether or not he is doing more harm than damage, the master of ceremonies finally says, "Okay! One more chance. What is 2 plus 2?" 

After 15 or 20 seconds, she replies, "Four."

The stadium of 80,000 blondes start chanting, "Give her another chance, give her another chance."