Needed Calculator

I've acquired over a million points and never used a calculator. I assured my students even the trig. questions can be done without a calculator. They may need to use some formulas like cos(A+B)=cosAcosB-sinAsinB but even then it will use the "special angles" which they are to know the ratios for. I'm sad to say I encountered my first trig. question which required a calculator-->> cos35=x/6.