Unit 2: Physics Sc 3200

Measurement and Calculations Significant Figures - are numbers or digits that carry value (meaning) in a scientific problem or equation

Rules for Counting Sig Figs There are five (5) rules we need to follow when counting sig figs: All non-zero numbers are significant ( that is numbers 1-9) Sandwiched zeros are significant Leading zeros are NOT significant Trailing zeros with a decimal are significant Trailing zeros without a decimal are NOT significant

All non-zero numbers are significant (that is numbers 1-9) Example: 123 has 3 sig figs 543.21 has 5 sig figs

2. Sandwiched zeros are significant Example: 1001 has 4 sig figs 901 has 3 sig figs

3. Leading zeros are NOT significant Example: 000004 has 1 sig fig 0202 has 3 sig figs .003 has 1 sig fig

4. Trailing zeros with a decimal are significant Example: 10.00 has 4 sig figs 1030.00 has 6 sig figs

5. Trailing zeros without a decimal are NOT significant Example 157 000 has 3 sig figs 1900 has 2 sig figs

Practice Questions!