# Tag Info

### Should one include the unit in the variable? E.g. should one write $x^\circ = 30^\circ$ or $x = 30^\circ$?

The usual physics convention is that variables have units built into them, so you don't need to (indeed, shouldn't) write the units separately. For example, Wikipedia writes In classical mechanics, ...

### What does research indicate about how one should treat units in elementary school?

The CRA approach says to move from concrete to pictorial to abstract concepts. The idea of numbers without units or identifiers is treating numbers as an abstraction, and a positive goal. You start ...

### Should one include the unit in the variable? E.g. should one write $x^\circ = 30^\circ$ or $x = 30^\circ$?

As far as the centimeters are concerned, I believe that both are possible, but there's a catch: $$3 cm+x=5 cm$$ Solution: $x = 2 cm$ => correct. $x = 0.2 dm$ => correct. $x = 0.02 m$ => ...
Accepted

### How to teach that $10000x^2$ c$^2$m$^2$ is wrong?

But $x^2$ m$^2$ and $10000x^2$ c$^2$m$^2$ are arguably both correct. The prefix ‘centi’ means a hundredth, and the convention \begin{align}\text{cm}^2:={}&(\text{cm})^2\\={}&(10^{-2}\text{ m})^...

### Should one include the unit in the variable? E.g. should one write $x^\circ = 30^\circ$ or $x = 30^\circ$?

This must certainly depend on the context. In the examples you present here, the units/dimensions do nothing, so I would just go ahead and forget them, taking them back in use to check if the answer ...

### How to explain square meters?

Peter answered how to explain the ideas to students. So I'll answer your second question: Is "square meter" a badly-phrased term? What would be a more appropriate term? It's not badly-...

### How to teach that $10000x^2$ c$^2$m$^2$ is wrong?

Although being a bit late to the question... The underlying problem I see is that we first expose our students to a math symbology where single letters are used to name things, and that simply ...

### How to teach that $10000x^2$ c$^2$m$^2$ is wrong?

I wanted to synthesize some of the discussion happening in the comments into an answer. To me, a statement like $$(100x\ \text{cm})^2 = 10\,000x^2\ \text{c}^2\text{m}^2$$ indicates that the student ...
### Should one include the unit in the variable? E.g. should one write $x^\circ = 30^\circ$ or $x = 30^\circ$?
I sometimes come across equations like I) $3 \text{ cm} + x \text{ cm} = 5 \text{ cm}$ where I would write II) $3 \text{ cm} + x = 5 \text{ cm}$. Aside from the fact that option I allows the units to ...