Island Hopping is a fantastic, visual way for children to learn how to round to the nearest ten. The link to the site with this lesson plan is included in this resource.
This packet includes four worksheets and one assessment to go along with this lesson. It also includes Keys for all of the worksheets and assessment.
This can be used to teach the CCS standard:
MCC.3.NBT.1 Use place value understanding to round whole numbers to the nearest 10 or 100.
It is designed for third graders.