Adding a math type fraction to a note when using CL

I am stuck on what is probably a simple solution. I would like for my Note to include a fraction when a certain option is selected from a Choice. I cannot seem to get a fraction to show up.

For example, within part of my code I have

when a=1 "Here is an example of a polynomial function:

`f(x)=(1/8)x^3-2x`` " Note, I don’t have two ’ at the end, but the post was converting it

Is it possible to make the 1/8 show up in math type/latex? I’ve tried using \frac{1}{8} with no luck.


Simple fix: you need two backslashes in desmos rather than the usual one.

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Yep! That did it! Thank you!!

I am having a similar problem but mine is coming from pulling the fraction out of a student response. The response we are looking for is 1/2x+3 but when I pull the input (input5.latex) and drop it into the content sink its displaying as \frac{1}{2}x+3. What am I missing here?

That sounds like you are on the right track. I think this is what you are looking for.

I am having a similar issue where I am pulling from a graph expression. Even when typed as a fraction in the graph expression, e.g. P=4/3, the note displays its decimal equivalent.

content: “Drag the green point to identify the number ${Graph1.number(“P”)}. Then, click the button see how close you are!”

Thank you for any help!

I think the note will always display as a decimal the way you described, but there could be a workaround. Maybe someone else has a better way, but here’s my thoughts.

One thing to try would be to have two separate equations in the graph component, such as N=4 and D=3? Then in the note, try:

content: "Drag the green point to identify the number \frac${graph1.number(“N”)}${graph1.number(“D”)}. Then, click the button see how close you are!"`

I can’t get that to format properly, so here’s the example:

Hmmm. I do like that work around; thank you! I am making an activity for grade 6, where I would like for the teacher to be able to input the number in the graph portion with minimal knowledge of the CL, definitely without going into the CL. So, I could use this for any screens that use fractions, and my version for decimals and integers. Not as clean on the back end as I would hope, but front end works rather well! Thank you! :+1:t3:

I just noticed something weird. If either the numerator or denominator is negative, the Note does not display well; it only seems to take the first character of the value of either N or D and moves the rest after the fraction bar. I changed the inputs to become random, and might include a third random variables that takes a value of either 1 or -1 and use the product to see if that works!

This is a pretty brittle example so use with extreme care: fractions? • Activity Builder by Desmos

Some things you should know:

  1. It simplifies the input (which might not be a problem if you’re using a value from the graph)
  2. it’ll work on fractions that can simplify to a denominator of 100 or less (and might have some cases where it doesn’t even do that).
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So… I’m getting there, and at this point I think it is time to share my activity. No issues on screens one and 2 where students are asked to plot an integer or a decimal.

On Screen 3, I have it pretty good, but only if the fraction has an initial numerator and denominator of an integer between 1 and 9 (no multi-digit, no negative). Both of those mess things up a bit when the note displays the fractions. This has turned out to be one of the more demanding (fun) activities I’ve created :smiley: and any further help would be appreciated!

Ordering and Comparing Rational Numbers • Activity Builder by Desmos

your activity was deleted. Any chance of sharing again?

Sure! There are a couple of versions :slight_smile:

Here is an example of what is completely usable: Ordering and Comparing Integers and Decimals • Activity Builder by Desmos

Here is an example of placing a fraction on the number line: Ordering and Comparing Rational Numbers • Activity Builder by Desmos. For this, @Jay helped me simply separate out the negative signs and compute (and display) them separately. I have since moved on from this project, but I believe it is completely usable :slight_smile:

Can you help me recognize that C must equal 1/6 to be correct please? Here’s what I tried. Neither one worked. This is in the CL and works fine without fractions.

correct: A=-1 and B=-1 and C=1/6 and D=6
correct: A=-1 and B=-1 and C=1\/6 and D=6

Similarly, I seem to be able to use negatives OR decimals, but not negative one half. A gives me an error here. Thank you in advance!

correct: A=-.5 and B=-2 and C=.5 and D=-6

C has to be a number, and numbers need a ones place, so try something like

 correct: A=-0.5 and B=-1 and C=frac.evaluateAt(1) and D=6
 frac = simpleFunction("\frac{1}{6}")

Thank you! I did find that -0.5 worked. I’m excited to try your fraction method! In the meantime I was doing C<0.16 and C<=0.17 so I’m glad to have something more precise. Thanks!

For fractions that evaluate as non-terminating decimals, it’s best to do as you did specifying a range, or using numericValue and rounding each value to a specified number of decimal places (i.e. C and 1/6), or the absolute value of the difference <= 0.01 (or some other tolerance).

Do you have a specific example of when the math input component would approximate a fraction differently than the simpleFunction fraction in the CL? I tried several fractions, but all of them worked-- even very large primes for both numerator and denominator.

I think @Jay has mentioned before that for things like this, simpleFunction should work well. If using numericValue, then there can be some rounding issues and a tolerance should be used.