
Reading
Archimedes and the golden crown
One day in ancient Greece, King Hiero asked a crown maker to make him a golden crown. At first, he was very happy with it.
“it’s a nice crown, isn’t it?” he asked his men. Later, however, he began to doubt that it was a real golden crown. “Is it made completely of gold?” he wondered. He sent it to Archimedes and asked him to find out the truth.
“This problem seems difficult to solve. What should I do?” thought Archimedes.
Archimedes was still thinking about this problem as he filled his bath with water. When he got into the bath, some water ran over.
“That’s it!” shouted Archimedes. “I know how to solve the king’s problem!”
Archimedes went straight to the palace to see the king. First, he weighed the crown and asked the king for some gold of the same weight.
Next, he put two pots into two big bowls and filled both pots with water. He put the gold into one pot and some water ran into the bowl. Then he put the crown into the other pot. This time, even more water ran into the bowl.
“Look at this,” said Archimedes to King Hiero. “A crown made completely of god displaces less water than a crown made of gold and another metal. This crown displaced more water than gold and another metal. This crown displaced more water than gold of the same weight, so I’m certain that it’s not completely made of gold.”
“The crown madder tricked me , didn’t he? What a bad man he is!” shouted King Hiero. He then sent the crown maker to prison.
More practice
Cao Chong weighs an elephant
One day, Sun Quan sent Cao Cao a present. It was a huge elephant. Cao Cao wanted to find out the weight of the elephant.
“What a huge animal it is! Can anyone tell me how to weigh it?” he asked the crowd around him.
“Can we get a large scale?” asked a soldier. However, no one could find a scale large enough.
“Can we cut it up?” asked another soldier.. “No. I don’t want to kill it,” said Cao Cao. Just then, young Cao Chong had a wonderful idea. “I can weigh the elephant!” he said “let me have a try.”
Cao Chong asked some soldiers to lead the elephant onto a boat. As the heavy animal walked onto it, the boat went lower into the water. Cao Chong drew a line on the side of the boat to mark how low it went. The elephant was then taken off the boat and the boat was filled with rocks until it went down again and water reached the line on the boat.
Cao Chong then weighed the rocks. He added up the weight of all the rocks and said, “This is the weight of the elephant.”
Cao Cao was very happy with his son. “My son is very clever, isn’t he” he said. Everyone agreed.
Unit 2 Great minds
Reading
Two geniuses
Many people consider Albert Einstein(1879-1955) a genius. This story about him shows that he also had a sense of humour.
Einstein often received invitations to explain his theories at different universities. On these trips, his driver Hans often said to him, “It’s a pleasure to drive a genius like you, Dr Einstein.”
One evening, on their way to a university, Einstein said, “ I’m so tired. I wish I could avoid giving my lecture tonight, Hans, but I don’t want to let my audience down.”
“I know what to do,” said Hans. “ I can give the lecture for you. You can trust me. I’ve listened to your lecture so many times that I’ve learnt it by heart. No one knows you at this university, so they won’t find out.”
So, they changed places. T the university, Hans was guided to the front of the hall. Einstein took a seat, listened to Hans give his lecture without difficulty, and joined in the applause at the end.
However, before Hans left, a man shouted, “I’d like to ask you a question.” He then asked a question so difficult that Hans had no idea what he was talking about.
Einstein turned pale. “Oh no!” he thought. “Now we’re in trouble. “But Hans just laughed and said, “That’s such an easy question that even my driver can answer it. Hans, please …”
Einstein stood up and answered the question perfectly.
They left the university, with Einstein driving. A little later, Hans offered to drive. “No,” laughed Einstein, “It’s a pleasure to drive a genius like you, Hans.”
More practice
Einstein and the little girl
One afternoon, Einstein was walking home from work. At the same time, a 12-year-old girl was walking home from school. They were soon walking side by side. The girl looked at him curiously from time to time.
“Pardon me,” the girl said, “but you look just like Albert Einstein.”
“That’s because I am Albert Einstein!” Einstein said.
“I don’t believe you,” the girl said. “Everyone knows that Einstein is a genius,. But you’re wearing your sweater backwards, so you can’t be very clever.”
Einstein began to laugh. “You’re the first person to be so honest with me, “he said to the girl. “it’s a pleasure to hear someone tell me the truth about my look.”
After that day, the girl often went to visit Einstein’s house after school. One afternoon, the girl’s mother went to visit Einstein. She asked him why he spent so much time with her daughter.
“Our friendship is easy to explain,” Einstein said. “Your daughter tells me the truth about my look and brings me cookies. In return, I help her with her Maths homework.”
