if you buy a 20 dollar thing with a 25 dollar gift card, do you still have 5 dollars?

If the gift card only allows one purchase, i.e., up to $25, you have nothing. Be sure to read the small print before using the card.

Yes obviously.

You subtract 20 from 25.

To determine if you will still have $5 left after buying a $20 thing with a $25 gift card, you need to subtract the price of the thing from the value of the gift card. Here's how you can do it:

1. Start with the value of the gift card: $25.
2. Subtract the price of the thing you want to buy: $25 - $20 = $5.

So, after buying the $20 thing with a $25 gift card, you will have $5 remaining.