Why are google slides opening as PDF documents when assigned to students?

Question

Some of my students use their phones to access Google classroom and complete assignments. 
Here is what I do: 
1. Create assignment and fill out title and instructions
2. Create new Google slide 
3. Make the slides 
4. Assign the work to students 
I have tried all three options 
1. Students can view file 
2. Students can edit file 
3. Make a copy for each student
The problem: 
When my students open the attachment, after the work is assigned, it does not open in a Google slide format. It opens as a PDF document. 
When the students submit the work or also submits as a PDF. 
I have joined the class as a "student" to see if I have the same issue, and I do. 
What am I doing wrong? 
I want my students to be able to open the attachment as a Google Slide. Not a PDF as my Google slides are interactive for my students.

Dierdre Shetler · Accepted Answer

Hi AK Rae,
 
I suspect this is what is happening: The students are clicking the "pencil" icon to edit the file. However, this doesn't actually edit the file, but opens up a PDF version of the file. In this case, they are basically writing on an overlay on top of the original file. 
 
Instead, they need to click the "sharrow" (box with arrow), which will force the editable file to open in the required standalone app (Slides, Docs, Sheets, etc.) Hence, they'll have to have all of the standalone apps on their phone as well. But then they will be able to actually edit the real file. 
 
On your end, as the teacher, assuming you want students to each be editing their own version, you need to add the attachment to the assignment to "Make a copy for each student." Then they'll all be able to open up their own editable version of the assignment, as long as they click the sharrow to edit the file. 
 
Dierdre Shetler
___________________________________________
STEM Instructional Technology Coach
Google Certified Trainer
Google Classroom Gold Product Expert