Classify -21.78
To classify -21.78, we need to determine its classification based on its properties.
- According to the number line, -21.78 falls to the left of zero, which indicates it is a negative number.
- -21.78 is a decimal number, as it contains a decimal point.
- It is not a whole number, as it is not an integer without any decimal places.
- It is also not an irrational number, as it is a terminating decimal (it does not continue infinitely).
- -21.78 is a real number, as it can exist on the number line.
Therefore, based on these properties, we can classify -21.78 as a negative, real, decimal number.