Includes all the digits that are known, plus one that is estimated

1. Measuring error = 1/10 of smallest division ii. iii. i.i.

What is the following measurement with the proper number of sig. figs.?

**Measure from the bottom of the meniscus

P A

Present vs. Absent If the decimal is present find the first non-zero digit starting from the left, count the digit and all digits to the right as significant Ex. 1: 200.0Ex. 2: If the decimal is absent find the first non-zero digit starting from the right, count the digit and all digits to the left as significant Ex. 1: s.f.2 s.f. 3 s.f.

Greater than or equal to 1 Find the first nonzero digit, everything after is significant **for zeros use the “after after” rule Is there a decimal point? Every nonzero number is significant **for zeros use the “Oreo cookie” rule Everything is significant YES NO

“Oreo cookie rule” Zeros between nonzero digits are significant Ex) 50,006 has five significant figures “After After rule” Zeros after a non zero digit and after a decimal point are significant Ex) has six significant figures

1.How many significant figures are in the numbers below? i.23,459 ii.300,004 iii iv sig figs 6 sig figs 2 sig figs 7 sig figs

A.Determine how many significant figures are needed B.Find the counting number— first nonzero number (starting from the left) C.Count how many sig. figs. you need D.Underline the last digit counted

E.Round the underlined digit by: 1.If the digit to the right of the underlined digit is less than five, the underlined digit stays the same and everything else becomes a zero place holder or gets dropped off 2.If the digit to the right of the underlined digit is more than five, the underlined digit is increased by one and everything else becomes zero place holder or gets dropped off **Five or more add one next door

i (3 sig. fig.) goes to ii.125,000 (2 sig. fig.) goes to iii.7,905 (1 sig. fig.) goes to iv (2 sig. fig.) goes to v (3 sig. fig.) goes to ,000 8, ( you can’t get three sig. fig. unless using Scientific Notation) A.Round each number to the specified number of sig. figs.

A.All digits in the coefficient are significant B.The exponent is not significant ×10 6 has 3 significant figures

1.Give the correct number of significant figures i x ii.2.69 x 10 iii.3.4 x (5) 2.69 (3) 3.4 (2)

2.Round each number to 3 significant figures i meters ii x 10 8 iii meter iv.9009 meters v x meters 4.36 x meters 9010 meters 1.78 x 10 -3

A.Round the answer to the same number of significant figures as the measurement with the least number of significant figures × 0.34 = sig. fig. 2 sig. fig. Answer ≈2.6 (2 sig. figs.)

× = sig fig. 3 sig. fig. Answer is 1.60 (3 sig. fig.) ⁄ 8.4= sig. fig 2 sig. fig Answer is 0.29 (2 sig. fig.)

1.Calculate using the appropriate number of sig. fig. i.23.4 x 56 ii x 5 iii x 23.5 iv.25/60 v / (1310.4) 7 (7.28) 1.5 (1.5275) 0.4 ( ) 49.0 (49)

A.Your answer must have the same number of digits to the right of the decimal point as the value with the fewest digits to the right of the decimal point = (1) (3) (2) Rounded correctly is 77.2  (1 place)

1.Add or subtract using the correct number of significant figures i ii.26.9 – 19 iii iv – (72.045) 8 (7.9) 81.3 (81.303) 11.4 ( )