Developing Number Sense: Principles of Counting
All concepts of number sense need to be actively taught.
The unitizing principle helps students develop the understanding of place value. This principle of counting is the last to be taught when all of the other principles are understood.
When students have developed the understanding that our math system uses base ten units. Objects are grouped into ten once a number is bigger than 9. And then, into sets of 100 when the number is bigger than 99.
When this occurs, students are aware of the concept that a one appears in the tens column and a zero in the ones column.
Hands on manipulation of objects, especially base ten or snap cube manipulatives, help students learn this concept.
Have students play games together with manipulatives and have them build the numbers to represent their ideas. For instance,”I had 5, but now I have 5 more. What number do I have?” Playing number games like this help children see this principle concretely and helps them to understand it in a deeper way.