# Checking correctness... I'm missing something

**URL:** <https://cl.desmos.com/t/checking-correctness-im-missing-something/2812>\
**Category:** Questions\
**Tags:** validation, correctness\
**Created:** [March 2, 2021, 5:59pm UTC](https://cl.desmos.com/t/checking-correctness-im-missing-something/2812 "2021-03-02T17:59:27Z")\
**Posts on this page:** 3\
**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:** [March 2, 2021, 5:59pm UTC](https://cl.desmos.com/t/checking-correctness-im-missing-something/2812/1 "2021-03-02T17:59:27Z")

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I have a problem where students are evaluating the derivative of a function with a constant “k” involved, using check marks and x’s as the suffix to tell them if they got it or not. I want it to not matter how they type the answer in (beyond being correct and using the correct variables involved), but I only get my check mark if I typed it exactly as I did in the CL. Can someone give me a better way for handling this?

Here’s the activity (or the slide I’m working on, anyway…)

> **[\[Copy of\] AP Test Prep 1 • Activity by Melissa Hesterman](https://classroom.amplify.com/activity/603e7c3ae472d60c9ddc3b6a)**
>
> Topics reviewed include IVT, the Fundamental Theorem of Calculus, curve sketching

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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:** [March 2, 2021, 7:56pm UTC](https://cl.desmos.com/t/checking-correctness-im-missing-something/2812/2 "2021-03-02T19:56:24Z")

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How’s this? This is another method using a graph. It can be pretty robust because you can use lists to make a lot of comparisons.

> **[\[Copy of\] \[Copy of\] AP Test Prep 1 • Activity Builder by Desmos](https://teacher.desmos.com/activitybuilder/custom/603e93d1691a1542f8bd04e3)**
>
> Topics reviewed include IVT, the Fundamental Theorem of Calculus, curve sketching

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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:** [March 2, 2021, 7:58pm UTC](https://cl.desmos.com/t/checking-correctness-im-missing-something/2812/3 "2021-03-02T19:58:17Z")

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That will work perfectly. Thank you so much!