Kids do not make the connections that angles in radians are numbers in decimals and that their trigonometric values are also numbers in decimals.
Kids do not understand that [math]\frac{\pi}{4} \approx 0.785[/math] and that [math]\cos(\frac{\pi}{4})=\cos(0.785) \approx 0.707[/math] .
Kids do not understand that [math]\frac{\pi}{2} \approx 1.5[/math] . (Okay it is 1.6 but 1.5 is good enough for a decent graph.)
They do not understand that [math]\cos(\frac{\pi}{6}) \approx \cos(0.524) \approx 0.866[/math] and that [math]\cos(\frac{\pi}{3}) \approx \cos(1.047)=0.5[/math]
