Calculator Error

Doing some small business bookkeeping today and found an error in the calculator app. Balance was $209.49 paid $100 balance 109.49. Paid again $200 calculator on computer said Credit $190.51. Should be CREDIT $209.49. Re entered thee data several more times the same ERROR is duplicated. I then pulled out a 12 year old computer, iPhone 6,8, and 15 only to get the same ERROR. Having a tablet laying around used a total different app for the calculator the changed it to an Algebraic Calculator...Just remembered one of the first tablets is in the office age 18 years. Now for fun I entered in the same data on a spreadsheet and. The same ERROR happened again...

An almost $20 error can mess up anyone's books...