Jake - I think the difference between being literate and numerate (although both important), is that so long as you can do the necessary maths to deal with life, then it doesn't matter at all whether you know an obtuse triangle from an isosceles one! If someone needs this information with regard to the job they're in, or hoping to get, then it matters a lot, but not being able to spell, or not knowing how to use words properly, just makes a person look ignorant. It's fine on here, for texts or when deliberately abbreviating in letters to friends, but when filling in forms, writing letters of importance, etc., a gramatically inadequate person's not going to get very far at all.