I’m assuming the $88.50 is pre-tax
$88.50 plus tax is $88.50 + ($88.50x6.5%, which equals $5.75 in tax)
$88.50 + $5.75 = $94.25 total with tax
If you have a $25 gift card, subtract that from your total with tax:
$94.25-$25.00=$59.25 total after you add tax and subtract the gift card