10.5 inches is 26.67 cm, which I would round off as 26.5 cm
5.5 inches is 13.97 cm, 14 cm
Europe/Asia is generations ahead of us using the metric system. I was a science teacher 40 years ago and tried to teach the metric system.... finally gave up 30 years ago. I have several meter sticks and 13 m tape measures. I really like working with metrics....
This is not meant as a criticism of anyone.