One.
In scientific notation 0.00000000006 = 6 x 10-11 which has 1 digit in the mantissa (the bit before the x 10-11) showing the number has only 1 significant figure.
The first significant figure is the first non-zero digit; then count the number of digits from there onwards until just zeros remain and stop counting then. Trailing zeros are not normally counted as significant, but trailing zeros after a decimal point (which would not normally be written) could indicate rounding to significant figures and be counted, eg 3.5897 to 4 sig fig is 3.590
Three of them which are 9, 0 and 9
There are four significant figures (the end part which is 6709). The 0 is significant there, because it is in between two significant figures.
That number has 4 significant figures: 6, 5, 7 and the final 0.
It has 3 because the 0's after the decimal point don't count as significant figures.
Three of them and they are 967
Four, the leading 0 is not significant but the trailing 0 is.
Three of them which are 9, 0 and 9
There are four significant figures (the end part which is 6709). The 0 is significant there, because it is in between two significant figures.
That number has 4 significant figures: 6, 5, 7 and the final 0.
in 890,000,000 there are two significant figures. A significant figure is a number that is not 0, except when 0 is between two non zero significant figures. e.g. 800900000 has 4 significant figures (8009), 7.56 has 3 significant figures etc.
The number 2.0e5 has two significant figures. The "2" and the "0" are both considered significant.
There are two. The two leading 0's re not significant figures.
It has 3 because the 0's after the decimal point don't count as significant figures.
Three of them and they are 967
Two or three. Integers ending in 0 are ambiguous cases.
There are three significant figures in 0.00701 because the initial zeros are non-significant and the 0 is significant because it is sandwiched between two significant numbers.
30006 has 4 significant figures: 3, 0, 0, and 6. Zeros between non-zero digits are considered significant.