Significant Figures and Rounding Counting Sig Figs Pacific

Significant Figures and Rounding

Counting Sig. Figs. Pacific a. k. a. : Present Start with first non-zero, go in direction Steps to Count # of Sig. Figs. 1. 2. 3. 4. See if decimal is present or not. Go from correct direction. Start counting at 1 st Non-Zero # Keep counting until you run out of #s Atlantic a. k. a. : Absent Start with first non-zero, go in direction

Examples 1. 300, 150 a. Decimal point absent – 5 sig figs 2. 300. 0 a. Decimal point present – 4 sig figs 3. 300 a. Decimal point absent – 1 sig fig 4. 0. 0000015 a. Decimal point present – 2 sig figs 5. 631. 10 a. Decimal point present – 5 sig figs

Rounding Sig. Figs. 1. Always start from the LEFT 2. Start counting at the 1 st non-zero # 3. Count to the correct # of Sig. Figs. 4. Round that # a. If that # is a 0 before the ones position, then turn to sci. not. and then round. 5. For every # after the rounded position a. b. If before decimal, turn to zero If after decimal, drop

Example – Round 0. 065930 to 2 S. F. 1. Always start from the LEFT • 0. 065930 2. Start counting at the 1 st non-zero # • 0. 065930 3. Count to the correct # of Sig. Figs. • 0. 065930 4. Round that # • 0. 065930 Final Answer: 0. 066

Example – Round 0. 065930 to 3 S. F. 1. Always start from the LEFT • 0. 065930 2. Start counting at the 1 st non-zero # • 0. 065930 3. Count to the correct # of Sig. Figs. • 0. 065930 4. Round that # • 0. 065930 Final Answer: 0. 0659

Examples: a) 135. 35 (4 S. F. ) b) 135. 35 (2 S. F. ) c) 1. 506 x 104 (3 S. F. ) d) 5. 80354 (3 S. F. ) e) 100 (2 S. F. )

Determining the Number of Sig Figs in Calculations •

Determining the Number of Sig Figs in Calculations •