1. It was overcast that day and it didn't rain. The wind blew strong for n times, and I came to school happily. In math class today, the teacher talked about yesterday's homework, and we took out our homework. The teacher told us one question after another, and I was very excited when I talked about the eighth question on the 95th face of my homework. Because this is a difficult problem that I can't think of other methods, I can't wait. I hope the teacher can give me some advice so that the whole class can listen to my methods.

But the teacher didn't let me answer. I thought there was only one way, but after listening to my classmates, I got a variety of answers. At this moment, I finally couldn't help raising my little hand. I have another good idea.

So, I stood by the blackboard and said in a hoarse voice, "My method is to draw them into a cross and divide them into four equal parts. We can find that each piece of green grass is just half the area ... "Say that finish, I breathed a sigh of relief. Today, I am very proud of my ideas, including the answers. There are so many ingenious methods for this little math problem. Mathematics not only exercises our intelligence, improves our logical thinking ability, but also makes us feel the joy of learning.

When we do arithmetic problems, we are most afraid of doing very complicated ones. At this time, clever calculation will come into play. Let me teach you a clever calculation method. If you encounter the calculation problem of "head-to-tail consistency", you can skillfully do this: multiply the number in the tenth place by the product of the number in the tenth place plus 1, then multiply it by 100, and finally add the products of the two numbers in the single digit. It's actually quite simple. First, 5+ 1x5=30, then 30x 100=3000, and finally 3000+(3x7)=302 1. In fact, you just need to follow the above method.