--- ## Basic Rules - *All* non-zero numbers are counted. > **$123 = 3$** - Zeros **between** two number are counted. > **$103 = 3$** - Trailing zeros **with any** decimal point are counted. >**$120. = 3$** - All ***TRAILING*** zeros **after** a decimal are counted. > .$120 = 3$ > > **$0.120 = 3$** >[!tip] >- Dont forget: **zeros that come after the decimal point DO NOT COUNT if they trail a number**. >$\color{LightCyan}\large 0.012\space\text{ only has 2 sig figs!}$ --- ## Addition and Subtraction - Your final answer may have no more significant figures **to the right of the decimal** than the **LEAST** number of significant figures *(past the decimal)* in any number used for solving the problem. **$1.0 + 2.00 = 3.0$** **$3.00 - 2.0 = 1.0$** --- ## Multiplication and division - The **LEAST** number of significant figures in any number of the problem determines the number of significant figures in the answer. *(You are now looking at **the entire number**, not just the decimal portion)*. **$10 * 2.5 = 30$** **$10 / 2.5 = 4$** --- ## Rounding - All numbers are rounded off to have the exact number of sig figs they are assigned. **$123$ with sig fig $2 = 120$ - [[Uncertainties]] can be thought of as sig figs and the math / rounding works the same. ---- #mainpage