Mathematical "Facts"According to Math Teachers
Mathematical "Facts"This page contains actual cases of mathematical "facts" that have been taught in American schools, where kids got marked "wrong" for correct answers when they disagreed with the teacher's "facts". No wonder kids are getting discouraged and turning off from Math!
8th grade, Devotion School, Brookline, MA
Their fact: (ab/2) is not the same as (1/2 ab)
The real fact: (ab/2) = (a * b * 1/2) = (1/2 ab).
Their reasoning: (ab/2) = (1/2 a) * (1/2 b) = 1/4 ab, not 1/2 ab.
9th grade, Brookline High School, Brookline, MA
Their fact: Given a line l on a plane, and a point on l, there exist infinitely many axes of symmetry to l through this point.
The real fact: There are exactly two axes of symmetry in the plane to any line l through a point on l: one collinear with l, and one perpendicular to l.
Their reasoning: Their definition of an axis of symmetry was based on paper-folding rather than on anything involving sets of points.
We welcome new submissions of mathematical not-so-facts, as experienced by you or your kids. Please use the same format as above and put "not so facts" in the subject line.
Last Edited: Sunday, January 05, 2003
