That was not long ago. Grandpa and I took the No.2 bus to the Youth Palace. Just as the bus was about to leave, 1 the bus just started at the same time as us. At this time, grandpa looked at the two cars in front and suddenly smiled and said to me, Zequn, grandpa has a question to test you, okay? I am confident to answer: good! Listen carefully. If the 1 bus runs every 3 minutes and the No.2 bus runs every 5 minutes, how many minutes will it take for the two buses to leave at the same time? After a pause, I said, Grandpa, your question still needs one condition: 1 Bus and Bus No.2 start in the same place. Grandpa listened to my words, suddenly patted his bald head and said with a smile, I am also very confused as a doctor of mathematics, and my questions are not rigorous enough, but Zequn thinks very well. Grandpa and I laughed happily. At this time, grandpa said, ok, now suppose it's the same starting point. What do you think is the solution? I thought about it and blurted out: 15 minutes again. Because 3 and 5 are prime numbers, finding the least common multiple of prime numbers is equal to the' product of these two numbers (35= 15), so 15 is their least common multiple, that is, it takes at least 15 minutes for two cars to start at the same time. Grandpa praised me: correct answer! 100 integral. Yeah! Listen to grandpa. I raised my hands happily.
In this case, I understand a truth: mathematical knowledge is really everywhere in real life.
Comments: Learning and applying mathematics in life is one of the ideas advocated by mathematics curriculum standards. The teaching question and answer between the little author and grandpa is full of interest and affection, which shows us how happy it is to learn mathematics!