Classroom Spotlight: Sorting Things Differently with Number Bonds in Kindergarten

 

Long ago, at the beginning of this school year, the concept of number bonds came up during our kindergarten Back to School Night.  “What do you know about number bonds?” we asked the parents. Parents responded:  “Number whats?”.  It’s taken a while, but kindergarteners are now deep into discovering how to make and manipulate numbers in ways that are new (and possibly confusing) to many adults.

Number bonds are a graphic representation of numbers and their parts.  The total 5, for example, can be considered as having 4 and 1 as parts.  No surprise, it can also have 2 and 3 as parts.  And let’s not overlook the possibility of 5 and 0.  As we introduce number bonds, we talk about interesting pictures and how totals can be sorted into different groups.  A simple image of five dogs lead to the possibility of the total 5 being broken up into three different groups: two yellow, one brown, and two white.  This same picture shows two standing dogs and three sitting dogs - another way to sort the five dogs. One dog is facing right, while four dogs face left- yet another way to sort.

Number bonds can be simple or complex.  After mastering various ways of making number bonds with a total of five, I asked a student recently to show me some ways to make number bonds with a total of 23.  Their first number bond showed parts of 20 and 3, which showed an understanding of place value.  Their subsequent number bonds showed off a wide range of creative understanding.

Many kindergarteners (and usually a few parents) are convinced that “real math” involves formulas: the more complicated the formulas, the better the math.  Of course there’s a place for computational complexity and we encourage that.  But often in life, the trick to figuring out a problem involves sorting it in a new way.  If you’re only focusing on dog color, you might not notice the different postures.  If you’re stuck with some complicated problem - consider the mighty number bond and how you might sort things differently.