How to Weigh an Elephant?
With the start of the new school year, this time we'd like to share a true story from Chinese history for kids. It is about a boy using his ingenuity to solve a difficult practical problem.
Nearly two thousand years ago (around 200 A.D.), in the country of China, there lived a boy named Cao Chong. His father Cao Cao was the King of China. When Chong was six years old, a foreign guest brought an elephant from a distant land to the courtyard of the palace as a gift to Chong’s father.
Chong was very excited to see an elephant for the first time, since there was no elephant where he grew up. All the people in the court were amazed by the gigantic size of the elephant. A man with strong arms and legs tried to lift one leg of the elephant, but it moved not an inch. “I bet the elephant is really heavy.” Someone in the crowd shouted, I will give my precious marble to whoever knows exactly how heavy this wonderful beast is.”
The King turned to the guest who brought the elephant and asked, “Do you know how much this elephant weighs?” “I’m afraid not, your majesty,” he replied. “Elephants are too big and heavy for our scales.” The King stood up and asked the crowd. “Who has a way to measure this elephant’s weight?”
Just as everyone was scratching their heads, Chong shouted, “I have an idea!” But the crowd was in doubt that a little boy knew better than all the wise grown-ups in the court. Chong whispered his idea into his father’s ear and pleaded, “Please just let me try.” The King nodded. Chong led the whole crowd and the elephant to a beautiful lake inside the palace, with a wooden boat next to the shore. Chong guided the elephant onto the boat. The weight of the elephant made the boat sink a lot in the water. Chong then asked a helper to mark the water line on the outside of the boat with a knife. Then he guided the elephant off the boat and back on shore. The mark rose with the boat and was now obviously above the water since the boat was so much lighter without the elephant in it. “What was the boy doing with all the loading and unloading of the elephant?” People became puzzled. “Don’t worry. I’m not done yet.” Chong smiled. He then ordered some helpers to put rocks into the empty boat. The boat started to sink slowly as rocked pile up, and the mark came closer and closer to the water. Chong asked them to stop at the exact moment when the mark met the surface of water. “Now we know that this elephant is as heavy as the pile of rocks in the boat!” Chong exclaimed. “Let’s bring a scale and weigh these rocks!” The rocks were weighed on the scale one by one. The scale wasn’t big enough for the elephant, but was perfect for the rocks. Helpers recorded the weight of each rock, “45 pounds, 36 pounds, 50 pounds…” When all the rocks had been weighed, Chong added their weights up and calculated the sum. “Father, I have the answer! The elephant weighs 9398 pounds.” Chong shouted with excitement. Loud cheers burst out from the impressed crowd. The King was so proud and the elephant seemed pleased too, raising its trunk and blowing water into the air.
Chong was very excited to see an elephant for the first time, since there was no elephant where he grew up. All the people in the court were amazed by the gigantic size of the elephant. A man with strong arms and legs tried to lift one leg of the elephant, but it moved not an inch. “I bet the elephant is really heavy.” Someone in the crowd shouted, I will give my precious marble to whoever knows exactly how heavy this wonderful beast is.”
The King turned to the guest who brought the elephant and asked, “Do you know how much this elephant weighs?” “I’m afraid not, your majesty,” he replied. “Elephants are too big and heavy for our scales.” The King stood up and asked the crowd. “Who has a way to measure this elephant’s weight?”
Just as everyone was scratching their heads, Chong shouted, “I have an idea!” But the crowd was in doubt that a little boy knew better than all the wise grown-ups in the court. Chong whispered his idea into his father’s ear and pleaded, “Please just let me try.” The King nodded. Chong led the whole crowd and the elephant to a beautiful lake inside the palace, with a wooden boat next to the shore. Chong guided the elephant onto the boat. The weight of the elephant made the boat sink a lot in the water. Chong then asked a helper to mark the water line on the outside of the boat with a knife. Then he guided the elephant off the boat and back on shore. The mark rose with the boat and was now obviously above the water since the boat was so much lighter without the elephant in it. “What was the boy doing with all the loading and unloading of the elephant?” People became puzzled. “Don’t worry. I’m not done yet.” Chong smiled. He then ordered some helpers to put rocks into the empty boat. The boat started to sink slowly as rocked pile up, and the mark came closer and closer to the water. Chong asked them to stop at the exact moment when the mark met the surface of water. “Now we know that this elephant is as heavy as the pile of rocks in the boat!” Chong exclaimed. “Let’s bring a scale and weigh these rocks!” The rocks were weighed on the scale one by one. The scale wasn’t big enough for the elephant, but was perfect for the rocks. Helpers recorded the weight of each rock, “45 pounds, 36 pounds, 50 pounds…” When all the rocks had been weighed, Chong added their weights up and calculated the sum. “Father, I have the answer! The elephant weighs 9398 pounds.” Chong shouted with excitement. Loud cheers burst out from the impressed crowd. The King was so proud and the elephant seemed pleased too, raising its trunk and blowing water into the air.
Comments
Post a Comment