Two. The first two zeros are just placeholders.
Four significant figures.
an infinite number of numbers
The figure 18.03 has a total of four significant numbers
One significant figure.
All of them are significant.
Four significant figures.
3
231.57 has five significant figures/numbers. All the numbers in 231.57 are significant.
.020 has two significant figures: 2 and 0 A significant figure are digits that contain meaning contributing to precision. All numbers are considered meaningful except for zero, unless zero is between two other numbers or tailing non zero numbers where a decimal is present.
an infinite number of numbers
The figure 18.03 has a total of four significant numbers
4 significant figures.
4 significant figures.
5 significant figures.
All of them are significant.
2 significant figures.
One significant figure.