National University
CAHINORC - INORGANIC AND ORGANIC CHEMISTRY [LEC]
NUR255
Name: Zardy Gabriel N. Andaya
CORNELL NOTES 1.3
Significant Figures
The Factor-unit method to solve Notes
numerical problems
Scientific notation and
calculations SIGNIFICANT FIGURES
What are significant figures? Significant Figures
‒ The digits in a number that
carry meaning about ITS
PRECISION.
Is there an another term for Significant figures are also called
significant figures? “sig figs” in short.
What kind of number does one Significant figures are numbers in
significant figure represent? a measurement that represent
the CERTAINTY of the
measurement, plus one number
representing an ESTIMATE.
REFLECTION
Significant Figures (sig figs) are digits that carry meaning in a
measurement, as it may represent a certainty or estimate of that specific
measurement.
, RULES FOR DETERMINING THE
SIGINIFICANCE OF ZEROS
Are preceding zeros in a 1. Zeros not preceded by nonzero
measurement are considered numbers are NOT SIGNIFICANT
as significant figures? FIGURES called Leading zeros.
What is a good example of Example: 0.00932, where 932
Rule #1 for determining the are the only significant
significance of zeros? numbers.
Are zeros located between 2. Zeros located between nonzero
nonzero numbers are numbers are SIGNIFICANT
considered as significant FIGURES called Buried or
figures? Confined zeros.
What is a good example of Example: 10045, where all of
Rule #1 for determining the these numbers are all
significance of zeros? significant numbers.
Are zeros located at the end of 3. Zeros located at the end of a
numbers if there is a decimal number are SIGNIFICANT FIGURES
point present are considered if there is a decimal point present
as significant figures? in the number called Trailing
zeros.
What is a good example of Example: 6.007, where all of
Rule #1 for determining the these numbers are all
significance of zeros? significant numbers.
REFLECTION
If a decimal point is present in the number, and zeros are sandwiched
between nonzero numbers and are at the end of a number are considered
significant figures, while zeros that are the start of a number does not.
, Answer obtained by multiplication
How do you determine how or division must contain the same
many significant numbers are number of significant figures (SF)
when multiplying two or more as the quantity with the fewest
of them? numbers of significant figures
used in the calculation.
What is a good example of Example:
determining the number of 4.325 x 4.5 = 19.4625
significant figures through (4 SF) (2 SF) = 2 SF
multiplication? = 19
Answers obtained by addition or
How do you determine how subtraction must contain the same
many significant numbers are number of places to the right of the
when adding or subtracting decimal (prd) as the quantity in the
two or more of them? calculation with the fewest number
of places to the right of the decimal.
What is a good example of Example:
determining the number of 5.325 + 5.5 = 10.825
significant figures through (3 prd) (1 prd) = 1 prd
addition or subtraction? = 10.8
RULES FOR ROUNDING NUMBERS
Do we round up significant 1. If the first of the nonsignificant
figures? figures to be dropped from an
answer is 5 or greater, all the
nonsignificant figures are
dropped, and the last significant
figure is INCREASED BY 1.
Example:
Give me an example of Round -0.17 to 1 decimal place
rounding up significant figures? = -0.2
When should we not round up 2. If the first of the nonsignificant
significant figures? figures to be dropped from an
answer is less than 5, all
nonsignificant figures are
dropped, and the last remaining
significant figure is LEFT
UNCHANGED.
REFLECTION
When multiplying or dividing sig figs, the quotient or product should have the
same number with the fewest significant numbers used in the calculation.
While, addition and subtraction uses the fewest number of decimal places.
CAHINORC - INORGANIC AND ORGANIC CHEMISTRY [LEC]
NUR255
Name: Zardy Gabriel N. Andaya
CORNELL NOTES 1.3
Significant Figures
The Factor-unit method to solve Notes
numerical problems
Scientific notation and
calculations SIGNIFICANT FIGURES
What are significant figures? Significant Figures
‒ The digits in a number that
carry meaning about ITS
PRECISION.
Is there an another term for Significant figures are also called
significant figures? “sig figs” in short.
What kind of number does one Significant figures are numbers in
significant figure represent? a measurement that represent
the CERTAINTY of the
measurement, plus one number
representing an ESTIMATE.
REFLECTION
Significant Figures (sig figs) are digits that carry meaning in a
measurement, as it may represent a certainty or estimate of that specific
measurement.
, RULES FOR DETERMINING THE
SIGINIFICANCE OF ZEROS
Are preceding zeros in a 1. Zeros not preceded by nonzero
measurement are considered numbers are NOT SIGNIFICANT
as significant figures? FIGURES called Leading zeros.
What is a good example of Example: 0.00932, where 932
Rule #1 for determining the are the only significant
significance of zeros? numbers.
Are zeros located between 2. Zeros located between nonzero
nonzero numbers are numbers are SIGNIFICANT
considered as significant FIGURES called Buried or
figures? Confined zeros.
What is a good example of Example: 10045, where all of
Rule #1 for determining the these numbers are all
significance of zeros? significant numbers.
Are zeros located at the end of 3. Zeros located at the end of a
numbers if there is a decimal number are SIGNIFICANT FIGURES
point present are considered if there is a decimal point present
as significant figures? in the number called Trailing
zeros.
What is a good example of Example: 6.007, where all of
Rule #1 for determining the these numbers are all
significance of zeros? significant numbers.
REFLECTION
If a decimal point is present in the number, and zeros are sandwiched
between nonzero numbers and are at the end of a number are considered
significant figures, while zeros that are the start of a number does not.
, Answer obtained by multiplication
How do you determine how or division must contain the same
many significant numbers are number of significant figures (SF)
when multiplying two or more as the quantity with the fewest
of them? numbers of significant figures
used in the calculation.
What is a good example of Example:
determining the number of 4.325 x 4.5 = 19.4625
significant figures through (4 SF) (2 SF) = 2 SF
multiplication? = 19
Answers obtained by addition or
How do you determine how subtraction must contain the same
many significant numbers are number of places to the right of the
when adding or subtracting decimal (prd) as the quantity in the
two or more of them? calculation with the fewest number
of places to the right of the decimal.
What is a good example of Example:
determining the number of 5.325 + 5.5 = 10.825
significant figures through (3 prd) (1 prd) = 1 prd
addition or subtraction? = 10.8
RULES FOR ROUNDING NUMBERS
Do we round up significant 1. If the first of the nonsignificant
figures? figures to be dropped from an
answer is 5 or greater, all the
nonsignificant figures are
dropped, and the last significant
figure is INCREASED BY 1.
Example:
Give me an example of Round -0.17 to 1 decimal place
rounding up significant figures? = -0.2
When should we not round up 2. If the first of the nonsignificant
significant figures? figures to be dropped from an
answer is less than 5, all
nonsignificant figures are
dropped, and the last remaining
significant figure is LEFT
UNCHANGED.
REFLECTION
When multiplying or dividing sig figs, the quotient or product should have the
same number with the fewest significant numbers used in the calculation.
While, addition and subtraction uses the fewest number of decimal places.
