Part-Part-Whole
Recognizing that a number can be broken down (decomposed) into smaller parts is
an essential understanding in number development. At the Primary level, being able
to recognize small groups as part of the larger group sets the foundation for
future addition and subtraction learning. At this stage we concentrate on breaking
a number into two parts.
Number Separating Machine
Pictured below is an example of our Number Separating Machine. You pour a set
amount of counters through the toilet paper roll and they get separated into the
two different parts of the box. This gives the students a hands-on and visual way
of understanding that a whole number (in this case the number five) can be made
up of smaller amounts and in different ways. Students pour their given number
through the Number Separating Machine many times to see how many different
ways they can make the given number.
Number Bracelets
We have also started working with number bracelets. Number bracelets, like the
Number Separating Machine, provide concrete practice for number combinations
and composing/decomposing numbers. These bracelets allow students to show
combinations for a number by sliding one bead at a time from one side to the
other. Students create as many combinations for a number as they can. As they
get more familiar with different combinations, they will also work in pairs to
practice missing addends by having one partner hide some beads under their hand
as the other partner determines the missing amount.