Noticed by telling a number of numbers. The unit must be autonomous. This unit may be standard units (SI), such as the s-meter units, such as cm or kg° c. Mm.
Observation by saying a number. Numbers must be marked with the unit. This unit is the standard DSI (SI) units such as meter, kilogram or other C-centimeter mm.
Observation by saying the number of digits.To have a unit directed it. This unit may be a standard unit persons (SI), such as meter, kg, or other units such as cm C mm.