0.80002 has 5 significant figures.

231.57 has five significant figures/numbers. All the numbers in 231.57 are significant.

The figure 18.03 has a total of four significant numbers

3 of them.

Because 10.00400 is 10.004, this has five significant digits (numbers).

There are 5 significant figures.

Two significant figures.

2 significant figures.

3 significant figures.

One significant figure.

5 significant figures.

It has five significant figures.

7 significant figures.

4 significant figures.

Three significant figures.

Four significant figures.

It has 4 significant figures

Answer: There are six. Answer: There is no such thing as "significant numbers". I assume you mean "significant digits". All digits are significant in this case - a zero (or more than one zero) between other digits is always significant.

One - the trailing zeros are not significant.

Three significant figures. 3 of them.

Two significant figures (2,8).

120.0 has 4 significant figures.

13.60 has 4 significant figures.

It has 3 significant figures. (1,5,8).

0.009 has 1 significant figure.

Two significant figures (8,9).

30.900 has 5 significant figures.

Two significant figures (3,4).

Two significant figures (2,3).

One significant figure (9).

1.000003 has 7 significant figures.

One significant figure. (5)

0.1668 has 4 significant figures.

250.95 has 5 significant figures.

2310 has 3 significant figures.

0.00909 has 3 significant figures.

0.0310 has 3 significant figures.

It has 3 significant digits.