# Sum numbers in one list based on duplicate text items in another list **URL:** \ **Category:** Lists-Logic\ **Created:** [December 27, 2018, 4:56am UTC](https://forum.dynamobim.com/t/sum-numbers-in-one-list-based-on-duplicate-text-items-in-another-list/30084 "2018-12-27T04:56:05Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Spencer-n](https://avatars.discourse-cdn.com/v4/letter/s/7bcc69/32.png) [@Spencer-n](https://forum.dynamobim.com/u/Spencer-n)\ **Post date:** [December 27, 2018, 4:56am UTC](https://forum.dynamobim.com/t/sum-numbers-in-one-list-based-on-duplicate-text-items-in-another-list/30084/1 "2018-12-27T04:56:05Z")
Hi, I would like to reduce the text list (in this case room names) and at the same time sum the corresponding index values in the number list (in this case areas). As per the graph extract. Any ideas on how to do this using either nodes or would it require code? cheers Spencer ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/c/9/c9476a85af9b73ed6376deb4fcfa390b22b2fde4.png) ---
**Author:** ![jacob.small](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/jacob.small/32/161030_2.png) [@jacob.small](https://forum.dynamobim.com/u/jacob.small)\ **Post date:** [December 27, 2018, 5:20am UTC](https://forum.dynamobim.com/t/sum-numbers-in-one-list-based-on-duplicate-text-items-in-another-list/30084/2 "2018-12-27T05:20:44Z")
List.GroupByKey Math.Sum (longest lacing). ---
**Author:** ![Spencer-n](https://avatars.discourse-cdn.com/v4/letter/s/7bcc69/32.png) [@Spencer-n](https://forum.dynamobim.com/u/Spencer-n)\ **Post date:** [December 27, 2018, 6:34am UTC](https://forum.dynamobim.com/t/sum-numbers-in-one-list-based-on-duplicate-text-items-in-another-list/30084/3 "2018-12-27T06:34:01Z")
Thanks very much Jacob 🙂 For others, nodes are as per extract. ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/6/5/658f0f1f7d5f0c90c6e5aa556ea26acfbbd1f386.png)