- Comparing quantities (more than and less than)
- Putting numbers in order
- Estimating quantities without counting
- Knowing when the answer to a math problem makes sense
Children should understand that the symbols 1, 2, 3, and so on stand for actual quantities of things and that mathematical statements, like 2 + 3 = 5 or 6 - 2 = 4, are ways of describing how those quantities relate to each other. In fact, many math education experts recommend that children first learn the concepts of addition and subtraction by combining or separating actual groups of objects (or pictures of objects), rather than by working with the symbols for plus (+) and minus (-).
In addition to understanding the importance of number sense, math educators must also recognize that when children are learning the meanings of the number symbols 1, 2, 3, and so on, they are actually learning several different ideas at the same time. For example, to understand the meaning of the symbol 2, a child would need to grasp all of these facts:
- The symbol 2 stands for the spoken word "two".
- The symbol 2 can stand for a certain number of objects.
- The symbol 2 can stand for the second position in a sequence.
- When counting, 2 comes after 1 and before 3.
- The written word two also stands for the spoken word "two", so 2 and two mean the same thing.
ABCmouse.com’s Math curriculum includes many different ways that children can learn about numbers and develop number sense.