At Nanjing Lukou Airport Terminal, my father asked me, "The plane is flying at 800 kilometers per hour, and it takes two and a half hours to fly from Nanjing to Sanya. How far is the distance between the two places? "

"The speed of the plane is 800 kilometers per hour, two hours is 1600 kilometers, and the remaining half hour is 0.5 hours, so 800 times 0.5 equals 400 kilometers, and the sum of the two is 2000 kilometers."

"Not bad!" Dad continued to ask, "If the plane accelerates to 1000 kilometers per hour, how long will it take?"

I quickly came to the conclusion that "2000 kilometers divided by 1000 kilometers equals 2 hours."

"If the plane is faster, 2000 kilometers per hour, how long will it take?"

"We only need an hour." I think the question is too simple.

Dad nodded with a smile. "But mom doesn't like flying. Do you have any good ideas? "

"Since mother is afraid of plane crash, hee hee! You can only ride a donkey! " I made a joke.

"If a donkey can walk about100km every day, how long will it take to get to Sanya?"

"20 days." We always play for five days, but it takes her more than 20 days to go to Sanya by bike. By the time she arrives in Sanya, my father and I may have returned to Nanjing!

"Have you found any patterns?" So that's what dad really wants to ask.

"In the case of constant distance, speed and time are inversely proportional. That is, the faster the speed, the shorter the time it takes. Conversely, the slower the speed, the longer it takes. " I thought about it and said.

"Great!" Dad praised me for understanding correctly. "You see, mathematics is actually quite interesting!" "