[9422WMR]

Divide by 7.
Equals 14.3% tip
$100/7=$14.29
14.29/100=.143 =%14.3

[Responsibility2nd]

My sister in law taught me a neat and easy trick.

In Texas the tax is 8.XX%. Depending on locality.

Remember - do not tip on the tax. Just the food and beverage.

Double the tax amount and include it. Adjust plus or minus as necessary.

Done.