Before I answer the question about which assessment to do after Grouping Tens and Hiding, I want to comment on something you said. Did you mean you will have teachers give Grouping Tens AFTER the place value instruction? In case you did, let me tell you what I would recommend instead.  The AMC assessments are primarily designed to give teachers the information they need BEFORE they begin instruction.  This is a big shift from what we are used to doing. We usually teach and then "test" to see who got it and who needs more instruction. However, because the AMC assessments determine the level of thinking a child has reached and the level of proficiency they have achieved, they can really help teachers provide appropriate instruction for each child. So for example, if a teacher gives Grouping Tens before instruction, she would know which children are still needing to count by ones, who is counting by tens, who can combine tens and ones but counts on to add or subtract 10 and who already thinks of numbers as composed of tens and ones and needs to move on to a different level.  The children would all be working with the stations but she would be watching for different things and interacting with the children differently depending on what the children need.

So, let's think about what this might look like in the classroom:

The whole class is working with a set of 8 Place Value stations. I stop to observe the children who are working on Paper Shapes.  I know that each of the children working there at the moment have different instructional needs.

I know that Matthew Needs Practice because he counted on to add 10 and counted back to take 10 away during the assessment. So I interrupt him in the middle of filling his Paper Shape and ask him how many tens and ones he has so far.  Then I ask him how many he would have if he made another ten.  I know he will probably need to count on to find out, but  I will continue to ask him that question for a few days knowing that he will eventually realize he knows the answer without counting. My questioning focuses him on thinking about what is happening and not just doing the task without thinking. 

I know that LeeAnn was Ready to Apply on the assessment because she could add 10 and take 10 away without counting. I challenge her by asking her to tell me how many she has on her Paper Shape so far and then to think about how many more tens it might take to finish the Paper Shape. I want her to begin thinking more about the actual quantities she is working with and the relationships between the numbers. So if she has 2 tens and 3 ones on the Paper Shape, I could ask her to think about what the total might be.  Or if she had filled the Paper Shape up about half way, I would see if she noticed that she could double the number to get a reasonable estimate. In the next day or two, I could ask her to add two Paper Shapes. Over time, I would be looking to see if she needed to actually move the counters to see how many tens and ones there are all together or if she could reorganize the cubes mentally. 

I know that Eddie Needs a Prerequisite. But I don't want to isolate him from the class. So I want him to do the stations along with the other children but I know that I can't expect him to answer the same questions I might ask Matthew or LeeAnn.  I listen to him count all the cubes on his Paper Shape to make sure he is counting correctly.  In a few days, I could begin asking him to snap the Unifix cubes together into ten sticks and see how many sticks he could make. 
If teachers realize that the assessments are to inform their instruction and not just "judge" their teaching, I think they will find them more useful and over time will find better and better ways to help each of their children to move along in their understanding.

So…if a student gets A's on all the tasks in Grouping Tens and at some point during the year gets all A's on parts 1 and 2 of Hiding, which assessment is the logical one to give the student next?

I would suggest going on to Two Digit Addition and Subtraction. If a child has some difficulty (gets an N or an I), I would go back and assess them on Ten Frames.

I met with all of my 2nd grade teachers recently about their Hiding Assessment data and this question came up.  They noticed that while assessing the number 7, the assessment also assesses one or two of the combinations of 6 and wondered why. 

Other numbers are included in the What if section of the assessment as a way of checking retention of combinations the children  learned previously and to see if they are flexible in thinking about the combinations. Children have a tendency to focus on what they are learning at the moment without connecting it to what they know so we want to continually ask them questions that will help them see how it is all related. I discuss this very briefly on p. 39 under Section 1 heading in The Hiding Assessment book. 

Kathy