The fundamental problem is here:
"but i do not feel comfortable teaching that in 1st grader and i do not even know how i would find the time to teach him individually."
A 1st grade teacher has not been trained in how to teach the math beyond the 1st grade level within the context of their curriculum (sigh), and teachers really do not have the time to consistently provide differentiated instruction. She's looking for curriculum that requires no instruction.
I'm honestly sympathetic to the problem. Her job likely depends on each kid mastering 1st grade material with no incentive to move kids beyond. She sees the magnitude of the issue in her classroom, and does not want to pass on more of an issue to this child's 2nd grade teacher. Time, classroom management, and teacher annual progress are not issues to sneeze at.
The only teacher either of my kids have had that consistently provided high quality differentiated instruction and curriculum was (1) the math teacher leader in the district, and (2) held DS after school for 5 minutes each day to provide the instruction.
This teacher needs to head to administration for help, not other teachers.
