2:1 英语怎么说

1+1=2 one plus one is two
2/2=1 two divided by two is one
1*3=3 one multiply three is three
3-1=2 three minus one is two
（摘自《魔法英语语法》）

一、加法

“加”用plus，and或add表示；“等于”用is，make，equal等词表示。
1 + 1 = ？可表示为：How much is one plus two?
1 + 2 = 3 可表示为：
One plus two is three.
One and two is equal to three.
One and two make(s) three.
One added to two equals three.
If we add one to / and to, we get three.

二、减法

“减”用minus或take from表示。
9 - 3 = ？可表示为：How much is nine minus three?
9 - 3 = 6 可表示为：
Nine minus three is six.
Take three from nine and the remainder is six.
Three (taken) from nine is six.

三、乘法

“乘”可用time（动词）或multiply表示。
2 × 3 = ？可表示为：How much is two times three?
2 × 3 = 6 可表示为：
Two times three is six.
Multiply two by three, we get six.
Two multipied by three makes six.

四、除法

“除”用divide的过去分词形式表示。
15 ÷ 3 = ？可表示为：How much is fifteen divided by three?
15 ÷ 3 = 5 可表示为：
Fifteen divided by three is five.
Fifteen divided by three equals / gives / makes five.

五、其他算式的写法和读法

1：2 读作 the ratio of one to two
15：3 = 5 读作 The ratio of fifteen to three equals five.
3的平方 读作 three squared
2的立方 = 8 读作 Two cubed is eight.
X的四次方 = Y 读作 The fourth power of X is Y.
4开平方 = 2 读作 The square root of four is two.
8开立方 = 2 读作 The cubic root of eight is two.
这样可以么？

a/one
half.
分数
表示分数时，分子要用基数词，分母用序数词。如果分子大于1，分母必须用复数形式：
1／3→a（one）third
2／3→two
thirds
1／4→a（one）quarter（或fourth）
3／7→three
sevenths
1／2→应读作a（one）half
＊比较复杂的分数如：24／789，多读作
twenty
four
over
seven
hundred
and
eighty
nine。

答案为：a
half
或者one
second
记住这句口诀：分母序数词，分子基数词，分子不为一，分母+s
如1/3：
one
third
1/4:
one
fourth
1/5:
one
fifth
2/5：
two
fifths
3/7:
three
sevenths
以次类推
希望对你游帮助

这样：2 vs 1

2 to 1 凑字数