I. Examples
1. This morning, I got out of the two-meter-long bed, went into the bathroom and picked up a one-meter-long toothbrush to brush my teeth. Then I wash my face and have breakfast. I'm going out with my father to measure how far a kilometer is. We started from the intersection of Northwest No.3 Middle School (Dad said it was the intersection of Chengyang Road and Zhenxing Road) and began to measure the distance from the dashboard with a motorcycle.
2, has been measured to the door of the Civil Affairs Bureau is exactly one kilometer. Dad and I stopped the car and looked back. Wow, how far it is! I can't even see the beginning. How long will it take me to walk such a long distance? Dad took out his cell phone and began to time. Let's go back. When I passed a crossroads, I observed the trees on the roadside and found that there was a tree every five meters.
3. The ginkgo trees on the roadside have all borne fruit. It has grown for several years, about 4 meters high. I walked 14 minutes and 9 seconds, and walked 1555 steps before I walked back to the starting point. I felt a little tired and thought: One kilometer is really long! When I got home, my father told me that I walked very fast. At this speed, I can walk more than 4 kilometers per hour! It's almost catching up with the speed of adults walking.
Let me calculate how far I have gone: 1000÷ 1555=? I couldn't figure it out, so I calculated it with a calculator and the result was 0.64. It turns out that every step I take is 0.64 meters on average, which is 64 centimeters. This is a big step. This time, I really know how far a kilometer is. I also estimated that it is more than 1000 meters from my home to school. Learning kilometers is really useful!
Second, kilometers
1, km, pinyin is qiān mǐ, a Chinese word, which means the unit of length, commonly known as km, and English is expressed by km (kilometers); Origin: 1790 In May, a special committee composed of French scientists suggested that the length of 1 meter should be defined as one ten thousandth of the distance from the equator to the North Pole on the meridian passing through Paris.
2. 1 km =1000m =10000m =100000m; The unit of length is equal to 1000 meter. Also known as "km" (symbol km).