評論
打印
Which is correct: "A dozen eggs is?" Or "A dozen eggs are?"
哪個是正確的：a dozen eggs 'is' 還是 a dozen eggs 'are'？
I remember being in elementary school, and my teachers making a big deal about the unit.
我記得上小學的時候，我們老師教了很多數量單位詞。
And I never really got that, until one day, I was in the grocery store, and I wanted to buy an apple, but I couldn't buy one apple. I had to buy a whole bag of apples.
但我從沒有學會，直到有一天，我到雜貨店買蘋果（an apple），不過我不能買一個（one apple），而是必須買一整袋。
So I did. I bought one bag of apples, I took it home, I took one apple out of the bag, and I cut it up.
于是我買了一整袋蘋果，把它拿回了家，我從袋子拿出一顆蘋果并切開。
And then I ate one slice.
然后吃了一片。
One bag, one apple, one slice. Which of these is the real "one"?
一袋、一顆、一片。哪個才是真實的“一個”？
Well, they all are of course, and that's what my elementary teachers were trying to tell me.
好吧，它們當然都是，這正是我的小學老師一直試圖告訴我的。
Because this is the important idea behind whole number place value, decimal place value and fractions.
因為這是一個關于整數、小數與分數的重要概念。
Our whole number system depends on being able to change what we count as "one".
我們所使用的整個數字系統要轉換我們所熟悉的“一”。
Our whole number system depends on being able to change units.
我們所使用的數字系統要能夠轉換成單位。
There are two ways to change units.
有兩個方式能夠轉換單位。
We can compose, and we can partition.
我們可以組合，也可以分割。
When we compose units, we take a bunch of things, we put them together to make a bigger thing, like a dozen eggs.
當我們組合單位時，把一大堆東西放在一起，讓它們變得更大，比如一打雞蛋。
We take 12 eggs, put them together to make a group, and we call that group a dozen.
我們把十二顆雞蛋放在一起，組成一組，然后我們叫這一組為一打。
A dozen eggs is a composed unit.
一打雞蛋就是一種組合單位。
Other examples of composed units include a deck of cards, a pair of shoes, a jazz quartet and of course, Barbie and Ken make a couple.
其他組合單位的例子包括：一副牌、一雙鞋、爵士四重奏。當然還有芭比和肯尼組成的一對情侶。
But think about a loaf of bread.
但想想一條面包。
That's not a composed unit, because we don't get a bunch of slices from a bunch of different bakeries and put them together to make a loaf.
它不是一種組合單位，因為我們不會從不同的面包店拿一堆面包片放在一起，變成一條面包。
No, we start with a loaf of bread and we cut it into smaller pieces called slices, so each slice of bread is a partitioned unit.
我們不這樣做，而是把一條面包切得更小，并叫它為一片面包，所以每一片面包就是一個分割單位。
Other examples of partitioned units include a square of a chocolate bar, a section of an orange and a slice of pizza.
其他分割單位的例子包括：一塊巧克力、一片柳橙，還有一片披薩
