0817 Ask 树华: 美国和中国数学PK！绝对值、二元二次方程到底谁学得早呢？

Our classes are difficult. In 7th grade, we learned 绝对值，平面直角坐标系，一元一次不等式组、二元一次及二次方程。So, how old are American students when they learn them?

我们的课程好难哦。7年级，我们学了绝对值，平面直角坐标系，一元一次不等式组、二元一次及二次方程。所以，美国学生在几年级要学这些呢？

Thanks, 凯凯！Good question! Everybody says that Chinese math is harder than American math, but what does that mean exactly? 

谢谢，Kaikai! 非常好的问题。每个人都说中国的数学比美国的数学还要难，但是这个问题到底是什么意思呢？

That question is really hard to answer, because American schools are very different from Chinese schools. 

这个问题很难回答，因为美国的学校跟中国的学校非常不一样。

Chinese schools have a standard curriculum. Every Chinese school should teach the same things to all students.

中国的学校有个标准课程。美国中国的学校应该教每个学生同一些内容。

But in America, all the schools are different. Every state has their own curriculum. 

可是在美国，每个学校都不一样。每个州都有不同的课程。

So, some students might learn 绝对值 in 6th grade, and others might not learn it until 9th grade. 

所以，有的学生会在六年级学绝对值，还有的学生9年级才学。

But things are changing! Starting in 2009, some states started using the common core curriculum. 

可是，这些都在变化中！2009年开始，有一些州开始使用美国的共同核心课程。

So, all states that use the common core should teach the same things to all their students, just like China.

所以，已经开始用共同课程的州会给所有学生提供同一些内容，跟中国的模式一样。

Now, not every state has adopted the common curriculum yet. I think there are 9 or 10 states that still don’t use it.

那么，不是每一个州都接受共同核心课程。好像还有大概9-10个还没有开始用。

But, because most states are using the common core curriculum now, I’ll tell you when the common core says students should start learning things like 绝对值 and stuff like that, and we can see if Chinese learn it earlier, or Americans learn it earlier.

可是，因为大部分州已经开始用了，所以我今天就会告诉你共同核心课程里面指定那年纪要学习绝对值等内容，然后我们看看是中国的学生还是美国的学生先学的。

So! Are you ready? Here we go.

所以！准备好了吗？开始啦。

First, 绝对值 in English is called “absolute value.” For example, the absolute value of negative 3 is 3.

首先，绝对值，英语中叫作absolute value. 比如说，-3的绝对值是3.

You said you learned 绝对值 in 7th grade. In the American common core, students learn absolute value in... 6th grade! That’s one year earlier!

你说你在7年级学的绝对值。在美国的共同核心课程，这就是。。。6年级学的！那就是早一年咯！

Next, 平面直角坐标系, in English is “Cartesian coordinates” or “graphing.”

下一个，平面直角坐标系，英语中叫作Cartesian coordinates或者graphing。

You said you learned it in 7th grade, and Americans learn it in... 5th grade! Now, in 5th grade, all they do is put points on the graph. But it’s still graphing.

你说你们7年级就学了。美国人在。。。5年级就学啦！那么，5年级的时候，他们学的才是把点点放在坐标系上的准确位置而已，但是这也是graphing吧。

Next, 一元一次不等式组, one-variable inequalities. 妈呀！

接下来，一元一次不等式组。

You said you learned it in 7th grade, and Americans learn it in... 6th grade, again!

你说你们7年级就学了。美国人在。。。6年级就学啦！又早啦！

But the next one is: 二元一次及二次方程，single-variable equations and quadratic equations.

可是下一个是：二元一次几二次方程。

Now, Americans learn single-variable equations in 6th grade, but we don’t learn quadratic equations until 9th grade. 

那么，美国人6年级就学了二元一次方程，可是9年级才学二次方程。

Now, I was very surprised to learn that American students learn most of these things before you said you learned them, in the 7th grade.

那么，我听到美国人学这些东西比你说的7年级还要早，就很惊讶。

But, just because Americans learn it earlier, does that mean their math is harder than Chinese math? 

可是，这些东西美国人学得早是不是说美国人的数学比中国还难？

I don’t know. Even if Americans learn something before Chinese do, that doesn’t mean they learn as much about it as Chinese kids do.

不知道。就算美国人学东西学得早，不一定说明他们学的跟中国的学生一样多。

Maybe they just learn the basics and then move on. 

有可能他们学一些表面的东西然后过了。

But whether or not Chinese math is harder than American math, American schools are changing a lot these days. 

可是不管谁的数学比谁难，美国的学校最近改变还是挺大的。

They’re already very different from when I was in school in the 90s, and I’m very curious to see what they will be like in the future!

已经跟我当年90年代上学的时候非常不一样。我非常好奇看到未来美国的学校会怎么样。