Pt. 2 – Wrong-Headed Lattice Multiplication Being Taught to Children

Sep 1, 2015 by

lattace math

“Pt. 2 – Wrong-Headed Lattice Multiplication Being Taught to Children” – by Nakonia Hayes


To read Pt. 1, please go to:


FROM NAKONIA HAYES:  I tracked the time it took Khan to use the traditional multiplication method and the lattice method. He spent 2 minutes and 56 seconds with the traditional method. It took him 5 minutes and 30 seconds with the lattice multiplication method–or twice as long.


If taking a class test for 50 minutes that had 20 multiplication problems similar to Khan’s examples, a student could solve 17 problems with the traditional method and 9 problems with the lattice method. Assuming the traditional student got them all correct, he would have a score of 85. If the lattice student had all answers correct, he would have a score of 45. Or, does the teacher use a different “cut score” for grading that is based on methods and time used?


With division, using the traditional method, Khan worked for 2 minutes and 40 seconds. He worked for 4 minutes and 46 seconds with the partial quotient method. Again, it took almost twice as long to get an answer. In a 50-minute class with 20 test questions on division problems similar to his example, a student using the traditional method could, supposedly, answer 19 questions. The student using partial quotient could answer 10 questions. Under common sense grading, the first student could earn a 95 and the partial quotient student, a grade of 50.


The lattice and partial quotient methods are indeed “creative” and “unique” and, therefore, assumed (by some educators) to be “more interesting” and “more fun” for students. It’s one thing to show students these methods as an example of “another way” of solving multiplication and division problems. It’s another to have them master traditional methods that have been used internationally for centuries and which have proven to be the basis of efficiency in problem-solving when building great cultures and countries. There really is something special about learning these historically productive methods, compared to the alternate “fun” methods that have no proof of transcendence with similar success stories.


To order Nakonia Hayes’ book, Saxon Math Warrior, please go to:



Donna Garner

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