# What’s the difference between a unit and a digit

Concept is different, nature is different, express method is different, function is different.1. The counting unit is the digital measurement unit, common decimal notation, the decimal is per the relationship between the adjacent two counting unit is a big unit equal to ten little unit, meaning that they are into rate is between 10, counting unit should contain two large integer part and decimal part, counting unit and digital is the corresponding relations, digital refers to write number,When numbers are arranged in a row, each number occupies a position, and these positions are called digits.From the right, the first place is the place, the second place is the tens place, the third place is the hundreds place, the fourth place is the thousands place, and the fifth place is the ten thousand place.2. The counting unit of natural numbers is 1, and any natural number is made up of several ones.The fraction also has the counting unit of the fraction or the fractional unit, the fractional unit is determined by the denominator of unit 1 divided equally, the fraction represented is the number of fractional units used to measure the number of things or the number of things order, the natural number starts from 0, one after another, forming an infinite collective.The set of natural numbers has addition and multiplication operations, the result of the addition or multiplication of two natural numbers is still a natural number, can also be subtracted or divided, but the result of subtraction and division is not always a natural number, so subtraction and division operations in the set of natural numbers is not always valid.3 when counting the counting units in a certain order, each counting unit of the position is called a digit, the integer digit from the low to the high arrangement of a digit, ten, hundreds, thousands……A number expressed in different digital number is different, the size of the collection of natural number set N refers to satisfy the following conditions, one of the N elements denoted by 1, N) of each element can be found in N an element as its successor, 1 not the successors of any element, different elements have different successors, any subset of M, N ∈ if 1 M,And as long as x is in M it follows that x’s successors are in M, so M is equal to N.