You need to set up a Kahoot quiz for this lesson. You could use the following one that has already been created.
Students then go to Kahoot.it and use the Code from the teacher view.
At the end of the quiz you can save the results as a Google Spreadsheet and then review them to inform you of the progress of some of the students.
Continue with your Rivers Challenge.
Share your Code and add it to the Studio.
Copy and paste the URL to your code into Google Classroom.