1. Precision in measurement

2. Significant Figures The number of digits that have meaning to precision of data Rules 1. All non-zero numbers ARE significant. The number 33.2 has THREE significant figures 2. Zeros between two non-zero digits ARE significant. 2051 has FOUR significant figures. The zero is between a 2 and a 5.

3. 3. Leading zeros are NOT significant. They're nothing more than "place holders." The number 0.54 has only TWO significant figures. 0.0032 also has TWO significant figures. 4. Trailing zeros to the right of the decimal ARE significant. There are FOUR significant figures in 92.00.

4. 5. Trailing zeros in a whole number with the decimal shown ARE significant. For example, "540." indicates that the trailing zero IS significant; there are THREE significant figures in this value. 6. Trailing zeros in a whole number with no decimal shown are NOT significant. Writing just "540" indicates that the zero is NOT significant

5. For Example… 123,000,000 has 3 significant figures. Trailing 0’s are not significant. 123,000,100 has 7 significant figures. 0’s stuck in between other digits are significant. 0.003604 has 4 significant figures.

6. Scientific Notation Method of abbreviating very large or very small numbers. Based on powers of 10. 123,000,000 is expressed as 1.23 x 10 8 This is because 10 8 would move the decimal 8 spots to the right.

7. Scientific Notation 123,000,100 is expressed as 1.23001 x 10 8 0.003604 is expressed as 3.604 x 10 -3 This is because 10 -3 would move the decimal place 3 spaces to the left.

8. Adding and Subtracting numbers in scientific notation. Numbers should be rearranged such that exponents are the same. Multiplying and Dividing numbers in scientific notation Numbers following exponent rules. Multiplying  Add exponents Dividing  Subtract exponents

9. (7.21 x10 4 ) + (2.4 x 10 3 )

11. (7.41 x 10 5 cm) x (8.2 x 10 2 cm)