Cardinal numbers (also called whole numbers, natural numbers, or counting numbers) are those used to count physical objects in the real world,
0, 1, 2, 3, 4 .....
They are integers that can be zero or positive.
They assume that the things being counted are not divisible. So we can have 4 cars, but never 3½ cars.
Formally, counting numbers are the set of all non-negative
Cardinal numbers are also called counting numbers.
Statistics can confuse you
You may have heard something like "the average household has 1.8 children". Obviously, every family has a whole number of children.
The average is found by adding up all the children and dividing by the number of households.
Once you do that division you no longer have a cardinal number. That result is a statistic and is actually a
real number -
one that can have fractional parts.
When we have a set of objects, the cardinality of that set is the number of objects it contains.
Other number topics
Numbers that have factors
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