Sig. Figs. and Rules

Question 1

True or False - The bold digits in the following folowing number are significant: 1.0789

Answer 1

True

Question 2

True or False - The bold digits in the following folowing number are significant: 1.0700

Answer 2

True

Sig Figs were created to reflect the precision of an instrument

For example, a mass balance weighs to 0.0000 digits. Because that balance is precise up to that fourth decimal point, we would include it when we report the mass of an object or substance. Therefore, zeros after a decimal point that trail a nonzero digit are always significant. For example: the zeros in 0.0000099 are not significant, however, these underlined zeros are significant 0.009900

Question 3

True or False - The bold digits in the following folowing number are significant: 1.070078

Answer 3

True

Zeros that are in between two non zero digits are always significant

Question 4

True or False - The bold digits in the following folowing number are significant: 0.0001

Answer 4

False

Leadning zeros are not significant

Becuase the digit 1 is in the ten-thousandths place, this number alone will indicate the precision of an instrument, the leading zeros are not significant because they do nothing to indicate the precision of a hypothetical measurement.

Question 5

True or False - The bold digits in the following folowing number are significant: 900000

Answer 5

False

Trailing zeros are not significant unless there is a decimal point

i.e. the zeros of 9000 are not significant but adding a decimal: 9000. makes all the zeros significant

Question 6

True or False - The bold digits in the following folowing number are significant: 1.00890

Answer 6

True

Remember, zeros between digits are significant

Question 7

True or False - The bold digits in the following folowing number are significant: 1.008900

Answer 7

True

Trailing zeros after a decimal are significant

Question 8

What is the final answer for the following calculation? 2.1+2.0000000001

Remember your Sig Fig Rules

Answer 8

4.1

When adding or subtracting, use the number with the least decimal places

For this question, we limit our Sig Figs to the tenths (0.1) place because of 2.1

Question 9

What is the final answer for the following calculation?
4-2.1

Remember your Sig Fig Rules

Answer 9

2

When adding or subtracting, use the number with the least decimal places

For this question, we limit our Sif Figs in the final answer to the nearest whole number because the number 4 limits our final answer to whole intergers in the ones place.

Question 10

What is the final answer for the following calculation?
75.00000/25.0

Remember your Sig FIg Rules

Answer 10

3.00

For division & multiplication, we use the number with least Sig Figs

For this question, 25.0 has only three Sig Figs, so our final answer must have three Sig Figs as well.

Question 11

What is the final answer for the following calculation?
(3.00000)(25.0)=?

Answer 11

75.0

For division & multiplication, we use the number with least Sig Figs

25.0 is again our limiting number, having only three Sig Figs. Therefore, our final answer must also have three Sig FIgs.