KWF said:
Why do you think that 1 mill = $(1/1000) cannot be expressed as $(1/1000)/1 mill?
Because these are two different types of statements. One is an equation and the other is not.
It's like comparing apples to oranges. They both equal fruit, but they do not equal each other.
Is there a way to rate your answers? Thankfully, no.
\(\displaystyle 1 \ \text{mill} \;=\; \frac{1 \ \text{dollar}}{1000}\)
This is called an "equation". It is a mathematical
statement that the quantity to the left of the equals sign has the same value as the quantity to the right of the equals sign.
If we divide both sides of this equation by 1 mill, then we get another
equation. We can't just throw away half the equation, including the equals sign!
\(\displaystyle \frac{1 \ \text{mill}}{1 \ \text{mill}} \;=\; \frac{\frac{1 \ \text{dollar}}{1000}}{1 \ \text{mill}}\)
The lefthand side of this new equation simplifies.
\(\displaystyle 1 \;=\; \frac{\frac{1 \ \text{dollar}}{1000}}{1 \ \text{mill}}\)
This resulting equation is a statement that the ratio on the righthand side has a value of 1.
If we now write only the righthand side (i.e., we erase the "1=" part), then we no longer have an
equation. All we have is a ratio; which is a new type of statement. The ratio itself and the equation from which it comes are not the same thing.
\(\displaystyle \frac{\frac{1 \ \text{dollar}}{1000}}{1 \ \text{mill}}\)
We can say that this ratio equals 1, but it does not make sense to say that it equals some equation.
Again, an equation is not a
number. An equation is simply a
statement that relates two numbers.
Here's an analagous scenario.
If I write 1 = 1, that's an equation, yes?
Now, if I divide both sides by 2, I get the following.
1/2 = 1/2
You're trying to claim that the number 1/2 has the same value as "1 = 1".
That claim makes no sense.
I mean, if somebody asks you, "How much is one-half?", and you answer, "One equals one", they will look at you funny because your answer does not make sense.
You're trying to do the same thing with 1 mill.
If somebody asks you, "How much is a thousandth of a dollar divided by one mill?", and you answer, "one mill equals a thousandth of a dollar", they will say, "That's not what I asked".
Your response gives them sufficient information to
determine the answer, but your response is not the answer itself (which is "1").
Again, I ask you: What motivated your question? I mean, what led you to think about this stuff?