One of them.
There are four significant digits in the number 1.071.
Three significant digits.
This number has seven significant digits.
4000000
250 million = 250,000,000. There are 9 digits in this number.
All four of the digits given are significant digits.
There are two significant digits in the number 83.
200,000,000 9 digits.
All numbers which are not "zero" are classed as significant digits. Therefore in the number 129 there will be three digits which are classed as significant.
There are 2 significant digits: 5 and 4
Two. All nonzero digits are significant.
There are four significant digits in the number 6.741.