I've used cheap scientific calculators that perform operations from left to right. It's awful when you are answering a uni exam and you don't know why the results you get looks fishy.

On computer calculators, I always type "1 + 2 * 3 =" as "2 * 3 =", "+ 1 =" because I learned the hard way that I can't asume that a calculator is going to respect order of precedence or not.