Using Common Content Knowledge to investigate solutions
Following the clinical interview activity, one of the facilitators asked the teachers to consider
the deal-then-split strategy from the EPLT for sharing five wholes among four people. Several
of the teachers within the whole group responded that the answer was 1¼, and when pushed by
the facilitator to further qualify their answer, Fatima responded to a colleague from the group
who stated, “you could also say that they also get a fourth – of all of the cookies.” Fatima drew
upon her Common Content Knowledge and clarified the idea of the referent unit saying, “For
the one and one-fourth cookies, your situation is ‘how much does each person – how many
cookies does each person get?’… But if you say ‘how much of a whole share does each person
get?’ [it’s] one-fourth of all 5 cookies.” Fatima’s CommonContent Knowledge assisted her in
investigating, and clarifying for the group, the solution offered by her colleague.