Reys Ch. 8

The number system that we use has four important characteristics. The first characteristic is place value. Place value is how the position of a digit represents it's value. Base of ten is next. Base means a collection. In our system, ten is the value that determines a new collection and is represented by ten. The third characteristic is the use of zero. Zero exists to represent the absence of something. Last is the additive property. Numbers can be summed with respect to place value. These properties make the systemefficient and contribute to development of number sense. Once children understand these characteristics, the formation and interpretation of numbers becomes a natural development.  Many counting and trading experiences are necessary, particularly grouping by tens. Using manipulatives, such as grouping or trading with straws or cubes are a few methods of developing place value. Place-value mats serve as a visual reminder of quantities involved and provide a bridge toward the symbolic representation of larger numbers. Establishing these bridges from the concrete to the abstract is critical in developing place value. Place value concepts are developed many years. This means that place value is not completely developed before operations are introduced, because experiences with adding, subtracting, multiplying, and dividing whole numbers develops additional competence and understanding. Also working with decimals in later grades will further extend place value concepts.Place- value concepts will be integrated and extended throughout elementary school.