Thursday, January 13, 2011

Learning the Relational Meaning of the Equal Sign




"Students who exhibit the correct understanding of the equal sign show the greatest achievement in mathematics and persist in fields that require mathematics proficiency like engineering."

- Education Research Report Blogspot, citing the research of Robert and Mary Caprano

As Robert Caprano notes students need to see and experience the relational meaning of the equal sign. Young students are quite familiar with its operational meaning, whereby the equal sign is used to indicate the result of a series of operations, such as 4+3=7. This is indeed a legitimate and pervasive use of the equal sign and one can open any advanced mathematics or science textbook to practically any page to find this use being employed. Hence, the calculator use of the equal sign is not incorrect; it is simply only one use of this sign.

An understanding of the relational meaning of the equal sign, on the other hand, as Mr. Caprano notes. would enable students, to provide the answer of 7 to the problem 4+3+2= __ + 2.

In studies involving more than 2500 students conducted with the assistance of researcher Larry Barber, the results are conclusive: students as early as the 4th grade can solve equations such as 4x+3= 3x+9, thereby demonstrating that a) they understand the relational meaning of the equal sign, b) they can understand the concept of an unknown and c) they can work with equations having unknowns on both sides of the equal sign. This research can be found on www.borenson.com.

A video of an 8-year old solving 4x+5=2x+13 can be found by going to YouTube and searching for Algebra Hands-On Equations.

What is particularly interesting about this approach is that students pick up the relational meaning of the equal sign in only a few lessons. The students EXPERIENCE the new meaning of the sign. They quickly learn that the correct value of the unknown will make both sides have the same value.

For teachers not using Hands-On Equations, I would recommend an approach whereby the students experience the relational use of the equal sign in gradually more complex examples. In other words, the teacher gradually enables students to develop meaning to expressions such as 10= 4 + 6, 7 +3 = 9 + 1, and 10 + 2 = 2 + 5 + 5. Next, the teacher omits any one of the given numbers and asks the class for the missing number. In this manner the student soon learns to correctly answer examples such as 4+3+2= __ + 2.

In summary, there exist sound pedagogical interventions to enable even young students to understand the relational use of the equal sign.