Class subjects

Last period all we talked about was spelling words corrently. I found that irritating considering it's not an english class. What does it matter if you add an apostrophe where it doesnt belong in economics class? Mr. Wethington once said enough, "E-N-U-F-F." When someone corrected him he had to explain to them that they were in math class. I hate when teachers take off for grammar mistakes, if its legible and easy to understand then what's the big deal. Only in english should these mistakes be corrected. Proper english should be used no matter what the subject, but points should not be deducted.