# Sig. Figs/Digits handout

IMPORTANT RULES -ATTACH THIS DOCUMENT TO YOUR NOTEBOOK FOR FUTURE REFERENCE

SIGNIFICANT FIGURES

All non-zero digits are significant.

Zeros located between non-zero digits are significant.

825 has three sig. fig.

2007 has four sig. fig.

When a decimal or mixed decimal ends in zero, the zero is significant. 43.270 has five sig. fig.

When a whole number ends in zero (with no decimal point), the zero is not significant. 400 has one sig. fig.

When a whole number ends in zero (with a decimal point), the zero is significant 450. has three sig. fig.

SCIENTIFIC NOTATION

a.

Place the decimal point after the first significant digit. b.

c.

Count the number of places between the old and the new decimal point.

If the number in the problem is less than one, express the number of places between the old and the new decimal d.

point as a negative power of ten 0.45 = 4.5 x 10

¹

If the number in the problem is greater than one, express the number of places between the old and the new decimal point as a positive power of ten.

625 = 6.25 x 10

²

CALCULATING WITH SIGNIFICANT FIGURES

Add or Subtract using your calculator, and round the answer to the least accurate decimal place. 1.23 + 0.1 + 16.529 = 17.859

=>

17.9

Multiplying and Dividing:

Multiply or Divide using your calculator and round the answer to the fewest number of significant figures.

(25.1) (3.9) (0.0016) = 0.156624 => 0.16

Exact Numbers including exact conversions (for example 1m=100cm) should never be utilized for the purpose of determining where to round an answer.

Integrated Rules will be discussed at a later date.

IMPORTANT RULES -ATTACH THIS DOCUMENT TO YOUR NOTEBOOK FOR FUTURE REFERENCE

SIGNIFICANT FIGURES

All non-zero digits are significant.

Zeros located between non-zero digits are significant.

825 has three sig. fig.

2007 has four sig. fig.

When a decimal or mixed decimal ends in zero, the zero is significant. 43.270 has five sig. fig.

When a whole number ends in zero (with no decimal point), the zero is not significant. 400 has one sig. fig.

When a whole number ends in zero (with a decimal point), the zero is significant 450. has three sig. fig.

SCIENTIFIC NOTATION

a.

Place the decimal point after the first significant digit. b.

c.

Count the number of places between the old and the new decimal point.

If the number in the problem is less than one, express the number of places between the old and the new decimal point as a negative power of ten 0.45 = 4.5 x 10

¹ d.

If the number in the problem is greater than one, express the number of places between the old and the new decimal point as a positive power of ten.

625 = 6.25 x 10

²

CALCULATING WITH SIGNIFICANT FIGURES

Add or Subtract using your calculator, and round the answer to the least accurate decimal place. 1.23 + 0.1 + 16.529 = 17.859

=>

17.9

Multiplying and Dividing:

Multiply or Divide using your calculator and round the answer to the fewest number of significant figures.

(25.1) (3.9) (0.0016) = 0.156624 => 0.16

Exact Numbers including exact conversions (for example 1m=100cm) should never be utilized for the purpose of determining where to round an answer.

Integrated Rules will be discussed at a later date.