Episode 37 · Season IV · S4.E3 · Nov 4, 2026 · 15:55

The Culture of Mathematics: Street Vendors, Written Tests, and Who Can See What a Child Knows (S4 E3)

In Recife, Brazil, in the early 1980s, researchers posed as customers and bought coconuts, popcorn, and lemons from five children who worked the street markets. The children got 98 percent of the arithmetic right. A week later, on paper, with the same numbers, they got most of it wrong. This episode follows that finding: what the children knew, why the written test could not count it, and the Brazilian mathematician who named the problem ethnomathematics the same year. Then it follows the method of looking to places where adults went to find what children already knew: teachers in Tucson visiting their own students' homes and coming back with funds of knowledge; a second adult beside the teacher in the far south of Thailand who speaks Patani Malay; community teachers hired from the villages in Cambodia's highlands and moved onto the state payroll. The rule underneath: the question is never whether the knowledge is there. The question is whether the teacher in the classroom can recognize it. The episode closes with the season's recurring question, would it take root?

Listen to The Cultural Context of Knowledge on one of your favorite podcast players.

In this episode

00:00A coconut vendor in Recife
01:37Where this episode sits
02:15The street and the school
04:00The knowledge behind the answers
05:50The home as a source
07:48The adults in the classroom
11:07Who decides what counts
12:29What children already know
13:21Would it take root?
14:22Do this this week, and next week

“The question is never whether the knowledge is there. The question is whether the teacher in the classroom can recognize it.

References (9)

01Carraher, T. N., Carraher, D. W., & Schliemann, A. D. (1985). Mathematics in the streets and in schools · British Journal of Developmental Psychology, 3(1), 21–29.
02D'Ambrosio, U. (1985). Ethnomathematics and its place in the history and pedagogy of mathematics · For the Learning of Mathematics, 5(1), 44–48.
03Freire, P. (1970). Pedagogy of the Oppressed · Herder and Herder.
04Moll, L. C., Amanti, C., Neff, D., & González, N. (1992). Funds of knowledge for teaching: Using a qualitative approach to connect homes and classrooms · Theory Into Practice, 31(2), 132–141.
05Nunes, T., Schliemann, A. D., & Carraher, D. W. (1993). Street Mathematics and School Mathematics · Cambridge University Press.
06Sadler, M. E. (1900). How far can we learn anything of practical value from the study of foreign systems of education? · Address, Guildford, England; reprinted in Comparative Education, 1(3), 1964.

Get the notes, the references, and the reading list.

Join the email list and get the written companion and full reference list for every episode, plus the series reading list to start.

Continue the season

All episodes →

036 · S4.E2

What Counts as a Match: Caste, Language, and the Question Underneath (S4 E2)

In a village primary school in rural India, researchers compared a child with herself: one subject taught by a teacher who shared her gender…

14:37

035 · S4.E1

The Language in the Room: Who Decides What a Child Learns In (S4 E1)

In January 1970, the University of Ife in Nigeria began teaching a group of primary children in Yoruba for all six years of school, with Eng…

16:56

034 · S4.E0

Season 4 Trailer: Whose Room Is It?

Season 4 of The Cultural Context of Knowledge follows one question around the world: who teaches whom, in whose language, and who decided. E…

2:30