<human>:  What are some tips to calculate sales tax?
<bot>: 
1. Determine the applicable sales tax rate. This may vary based on both the state and the type of product or service being purchased.
2. Calculate the applicable sales tax by multiplying the applicable rate by the total sale amount.
3. Make sure to include any applicable local or county taxes that may apply.
4. If the item being purchased is tax-exempt, make sure to have the appropriate documentation in order to avoid paying sales tax.
5. Always double check calculations to ensure accuracy.