Building Blocks

Earlier this year, I had the opportunity to delve into the world of elementary mathematics, working along with a team of K-12 mathematics education researchers.  As a part of a professional development activity, an elementary teacher taught us (a group of adult 2nd graders) how to add: 257+138.

We were asked to represent the problem with base 10 blocks, an easy enough task for adult 2nd graders such as ourselves.  What became immediately obvious to me, amazingly so in fact, was the strength behind the use of base 10 blocks in helping students make sense of the mathematical task!


Easily and almost intuitively, 257 is transformed into 2 hundreds, 5 tens and 7 ones, and 138 into 1 hundred, 3 tens and 8 ones, which makes 3 hundreds, 8 tens and 15 ones. With a little extra thought, 15 ones can be regrouped into one 10 and 5 ones, making 3 hundreds, 9 tens and 5 ones or 395 in total.

Of course, an algorithm (a procedure or set of rules) may be developed later for efficiency, but it may initially look a little more like this, to resemble natural mental mathematics.

What a dramatic difference in learning for children when understanding is built using tools that support true learning, in classrooms where sense-making is the goal rather than memorization.    
I confess ignorance.  But I hope that this is a technique being used in Jamaican primary classrooms, as children learn two and three digit addition and other mathematics concepts, so that they are actively enjoying and making sense of mathematics, and not merely juggling numbers within meaningless algorithms.    

Margaret Campbell is an Advisory Board member of Reggae Math Foundation, the Principal of St. George's College, an all-boys' high school in Jamaica, Hubert Humphrey Fellow (Fulbright Fellowship), and a member of the National Mathematics Advisory Committee, Jamaica.