# Locking a Moveable Point with the Action Button

**URL:** <https://cl.desmos.com/t/locking-a-moveable-point-with-the-action-button/3253>\
**Category:** Questions\
**Tags:** validation, correctness\
**Created:** [May 7, 2021, 8:29pm UTC](https://cl.desmos.com/t/locking-a-moveable-point-with-the-action-button/3253 "2021-05-07T20:29:28Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![MathLady](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/mathlady/32/423_2.png) [@MathLady](https://cl.desmos.com/u/MathLady)\
**Post date:** [May 7, 2021, 8:29pm UTC](https://cl.desmos.com/t/locking-a-moveable-point-with-the-action-button/3253/1 "2021-05-07T20:29:28Z")

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Hello! I am trying to create an assignment where students are creating a sign line for a rational function by dragging images (attached to moveable points) into place. I want them to be able to see what they got correct (handled) but also not be able to change their answers after they check it. Is this possible? Here’s the activity so far:

> **[Sign Line Assignment • Activity by Melissa Hesterman](https://classroom.amplify.com/activity/609584914d52a357eba1047e)**
>
> by Melissa Hesterman

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**Author:** ![Daniel\_Grubbs](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/daniel_grubbs/32/719_2.png) [@Daniel\_Grubbs](https://cl.desmos.com/u/Daniel_Grubbs)\
**Post date:** [May 7, 2021, 8:49pm UTC](https://cl.desmos.com/t/locking-a-moveable-point-with-the-action-button/3253/2 "2021-05-07T20:49:03Z")

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Check this thread:

> [@Lock points after submission](https://cl.desmos.com/t/lock-points-after-submission/3208/3):
>
> Make your movable point, A, using sliders. Make a second immovable point using same sliders. Make a number, say n, in the CL linked to the submit press count. Use that to conditionally display the movable point. A=(x1,y1 {n=0}) (Drag should be on) B=(x1,y1) (Drag should be off) Graph CL: number(`n`): button.pressCount

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**Author:** ![MathLady](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/mathlady/32/423_2.png) [@MathLady](https://cl.desmos.com/u/MathLady)\
**Post date:** [May 7, 2021, 9:43pm UTC](https://cl.desmos.com/t/locking-a-moveable-point-with-the-action-button/3253/3 "2021-05-07T21:43:51Z")

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Thank you! I was sure there must be a post somewhere but couldn’t find it. That worked!

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<div class="post-metadata">

**Author:** ![MathLady](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/mathlady/32/423_2.png) [@MathLady](https://cl.desmos.com/u/MathLady)\
**Post date:** [August 24, 2021, 6:06pm UTC](https://cl.desmos.com/t/locking-a-moveable-point-with-the-action-button/3253/4 "2021-08-24T18:06:20Z")

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Hey, would you be willing to look at this activity? I’ve tried doing what you described and it’s not locking the points in. I’m not sure what I missed. (I do know there are ordered lists but wanted the problems randomized… thus using the graph to try it.)

> **[SMIII Honors: Unit 3 Lessons 1-3 • Activity Builder by Desmos](https://teacher.desmos.com/activitybuilder/custom/612524ad6d815d1069c0a80f)**
>
> 1. Writing the equation of a logarithm given the graph.
> 
> 2. Graph a logarithm given it's equation.
> 
> 3. Expand a logarithm using properties of logarithms.
> 
> 4. Ordering logarithms from least to greatest.

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**Author:** ![MathLady](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/mathlady/32/423_2.png) [@MathLady](https://cl.desmos.com/u/MathLady)\
**Post date:** [August 24, 2021, 7:48pm UTC](https://cl.desmos.com/t/locking-a-moveable-point-with-the-action-button/3253/5 "2021-08-24T19:48:24Z")

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Never mind! I got it working!