Only one at a time.
ten (0-9).
The number system we commonly used, known as the decimal system, has 10 digits (0 to 9). It is possible to use other number systems, with a different number of digits. Any numbering system based on the same principle (the principle of place-value) must use 2 or more digits.
In the decimal number system, the largest digit that can be used in each place value is 9. Place values increase by a power of 10 as you move from right to left, so the ones place can hold digits 0-9, the tens place can hold digits 0-9, and so on. The largest digit in each place value represents the highest value that can be assigned to that position in a number.
There are two and they are used for 'place value holders'
The 'zero' symbol is used as a place value holder,and it can hold any place.
The hexadecimal system is base 16.
In each place value there are only 10 digits that can be placed, 1,2,3,4,5,6,7,8,9,0. At that point then next place value is used. A different place value system in computers is the based two system. Its number system goes like this 0=0 1=1 10=2 11=3 100=4
Place value is not used in the Roman numeral system.
381 digits.
The ones column are in single digits and if there are none then the 0 digit is used.
Three digits.
A place value chart is used to help understand the value of each digit based on the place or position.