Significant Figures

Rules: #1 – Nonzero digits are significant 19 311 7862 1,237,983 #2 – Zeros between significant figures are significant 109 5002 6507 1,000,341

Rules #3 – Final zeros after a decimal are significant 10.0 234.00 2986.000 10000.00 #4 – Zeros that are placeholders are NOT significant 10 0.0003 350,000 0.099

Rounding When rounding to a specific amount of significant figures: In scientific notation, all numbers preceding “x10” are significant 5-9 as next digit: round up 1-4 as next digit: round down If you end up with zeros that need to be significant, but are not: Add a decimal at the end of the number All previous digits are then significant 100 rounded to 3 significant digits = 100. Add a bar over the final significant zero 100 rounded to 2 significant digits = 100

The Quick Method: If there is a decimal, count all digits to the right of the first nonzero digit as significant. 0.00150 0.0005 10.010 10,120.0 If there is NOT a decimal, count all digits to the left of the first nonzero digit. 10,000 230,450 250 1,205,375,000