significant didgets

Question 1

How many significant digits are in the number 0.00452?

Answer 1

3 significant digits (4, 5, and 2; leading zeros are not significant).

Question 1

Are trailing zeros significant?

Answer 1

Trailing zeros are significant if they are after a decimal point. For example, 2.300 has 4 significant digits.

Question 2

How many significant digits are in the number 500?

Answer 2

It depends on the context:

1 significant digit (if no decimal is shown).
3 significant digits (if written as 500)

Question 3

Why are the digits 7 and 4 in 74.0030 significant?

Answer 3

All nonzero digits are always significant.

Question 4

Why is the zero between 4 and 3 in 74.0030 significant?

Answer 4

Zeros between nonzero digits are always significant.

Question 5

How many significant digits are in 0.00560?

Answer 5

There are 3 significant digits: 5, 9 and the zero after it.

Question 6

How many significant digits are in 4500?

Answer 6

There are 2 significant digits: 4,
5, because there is no decimal point to indicate that the trailing zeros are significant.

Question 7

How many significant digits are in 0.03040?

Answer 7

There are 4 significant digits: 3, 0
4, and the trailing zero.

Question 8

How many significant digits are in 900.0?

Answer 8

There are 4 significant digits: 9, 0,
0, and the trailing zero (because of the decimal point).