Default Calculator has pop up ads

After many years of using iPads and the “default” calculator, suddenly I’m getting these huge loud advertisements. These are happening right in the middle of calculating something that has become very disruptive and I find myself not wanting to use the calculator any longer.

After all this time, if it’s a third-party app of which I did not download, all the iPads I have had, I’ve used the calculator that was already there. Thank you.

Apple iPad Air 4

Ver. 18.6.2