It is called the digital sum. If you keep doing it until you reach a single digit answer, it is called a digital root. The term digital root is sometimes also used for the digital sum.
For example,
3042 gives the digital sum of 3+0+4+2 = 9 which is also its digital root.
but
3047 gives the digital sum of 3+0+4+7 = 14 and the digital root is 1+4 = 5.
They are called the digital roots.
The different digits have different values.
Individual digits within a number have place values, not whole numbers.
A single digit in a number can have a place value. A number with several digits cannot.
If it's a one-digit number then any 1-digit number will do (0...9) 2-digits numbers : ab=10a+b=a+b it's not possible unless a=0 For 3-digits: abc=100a+10b+c=a+b+c => 100a+10b = a+b it' not possible unless a=b=0 And so on...
The correct answer is "expanded form".
They are called the digital roots.
The different digits have different values.
Individual digits within a number have place values, not whole numbers.
Any even number.
A single digit in a number can have a place value. A number with several digits cannot.
to show the cardinal and face values
If it's a one-digit number then any 1-digit number will do (0...9) 2-digits numbers : ab=10a+b=a+b it's not possible unless a=0 For 3-digits: abc=100a+10b+c=a+b+c => 100a+10b = a+b it' not possible unless a=b=0 And so on...
Zero or five.
Mutilply the values of the digits.
They make the numbers invisible to the people at Answers.com, possibly.
infinite number of digits after the decimal point -- pi does not have a finite value.