Focal Students

Looking at two of my focal student's developing number sense:

K:
During round one of the data collection, K drew 3 kids playing to represent the number 3.
In round 2, she drew 6 2two different ways using simple shapes (circles and triangles) opposed to an elaborate drawing.  In round 3, she showed the number 10 two ways using circles and a number sentence.  Round 4, I asked about the number 12, she was able to show it 4 ways with using symbols and numbers.


I:
First, he showed 3 similarly to the way K did by drawing 3 kids.  In round 2 he shows six circles in 2 ways but on one side, it is unclear that there are two separate groups to make 6.  When asked to show 12, he drew 12 kids in no particular grouping and only in one way. 

This leads me to wonder what understanding does Kamaya have that enables her to show numbers in many ways and use multiple ways to represent the groupings?  How can I bring all of my students to that level of understanding.  I have several students like I who are still not seeing number as something that can be manipulate and broken apart in many ways.  I feel like at this pint, I have 5 rounds of "exit tickets" that go up to the number 12 but I still need to delve deeper into how I am teaching and how the students are thinking.  This will help me get to my inquiry question which is "how do kindergarteners develop number sense?"