Do I need a space before "+", "-", "*", and "/"?<br/><br/>For example, which one is correct?<br/><br/><br/><br/>“a * 3 + 2 / b = c” or “a*3+2/b=c”<br/><br/><br/><br/>“((d * e) - f) * 2 = g” or “((d*e)-f)*2=g” <br/><br/><br/><br/>In addition, I would like to know the standard I can refer to or I should follow <br/><br/>when I am not sure whether a space is needed before a measurement unit.<br/><br/>For example, cm, kg, MB, t (ton), l (liter), V (volt), h (hour), Hz, %, etc. etc..<br/><br/><br/><br/>Thank you in advance for your help.