units.
one byte
If you mean 100,000,000 (9 digits) then its called one hundred millionif you ment 1,000,000,000 (10 digits but 9 zero's)then its called a billion
It's called 'rounding' - either up or down.
The digits that are reported in an answer are called significant figures.
Terminating Decimal
Decimal
significant digits
Significant Digits.
significant digits. for short they are called "sig. figs."
It is a decimal fraction.
repeating or recurring decimals
toes or fingers are also called digits.