a calculator with a history being superior was my first thought too. there are advantages to this approach too, however. The history is selective, so if you make a mistake/typo, that isn't now permanently in your history as a footgun to go back to and re-make. here you have two states and you have full control over them.

of course you could also just have a history where you can delete individual items, but this also makes the interface more complicated and might not be as intuitive (and requires more discipline)