Change license from CC BY 4.0 to CC BY-NC-SA 4.0

README.md

@@ -1,5 +1,5 @@
 ---
-license: cc-by-4.0
+license: cc-by-nc-sa-4.0
 task_categories:
   - visual-question-answering
   - image-classification
@@ -95,7 +95,7 @@ dataset_info:
 [![Project Page](https://img.shields.io/badge/Project-Page-blue?style=for-the-badge&logo=googlechrome&logoColor=white)](https://bbsngg.github.io/ScratchMath/)
 [![Paper](https://img.shields.io/badge/Paper-PDF-red?style=for-the-badge&logo=adobeacrobatreader&logoColor=white)](https://bbsngg.github.io/ScratchMath/paper/ScratchMath_AIED2026.pdf)
 [![Code](https://img.shields.io/badge/Code-GitHub-black?style=for-the-badge&logo=github&logoColor=white)](https://github.com/ai-for-edu/ScratchMath)
-[![License](https://img.shields.io/badge/License-CC_BY_4.0-green?style=for-the-badge)](https://creativecommons.org/licenses/by/4.0/)
+[![License](https://img.shields.io/badge/License-CC_BY--NC--SA_4.0-green?style=for-the-badge)](https://creativecommons.org/licenses/by-nc-sa/4.0/)
 
 </div>
 
@@ -185,4 +185,4 @@ If you use this dataset, please cite:
 
 ## License
 
-This dataset is released under the [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) license.
+This dataset is released under the [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/) license.