Question

How many significant figures are in 400..

Answer 1

Answer:

3 significant figures are in 400..

Explanation:

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

Rules for significant figures:

1. Digits from 1 to 9 are always significant and have infinite number of significant figures.
2. All non-zero numbers are always significant. For example: 654, 6.54 and 65.4 all have three significant figures.
3. All zero’s between integers are always significant. For example: 5005, 5.005 and 50.05 all have four significant figures.
4. All zero’s preceding the first integers are never significant. For example: 0.0078 has two significant figures.
5. All zero’s after the decimal point are always significant. For example: 4.500, 45.00 and 450.0 all have four significant figures.
6. In a non decimal number like 30 , there are 1 significant figure but number in which decimal is written after zero then all the zeros will become significant.

Given = 400.

As we can see that decimal point is present  after 0 which makes the all the zeros of the number significant.

So, significant figures are in 400. is 3.

Answer 2

Answer:

There are 3 significant figures in 400.

Explanation:

All non-zero digits are significant, therefore the 4 is significant. Zeros after the number are only significant if there is a decimal point in the number, therefore the two zeros are also significant.