#color(red)("Not using a calculator")#
#color(purple)("Doing this a sort of cheating way")#
Method:
Known that #1/3xx1/2=1/6#
so #5xx(1/3xx1/2)=5/6#
#color(green)((5xx1/3))color(red)(xx1/2)=5/6#
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Write as #3+5/6#
#color(green)("Consider just the "5/3#
#color(green)("It is known that "1/3 = 0.33333....)#
#color(green)("so "5xx1/3 = 5xx0.3333....)#
#color(green)(=1.666666...)#
#color(red)("Now consider the "xx1/2)#
#color(red)(1.66666..xx1/2=0.83333..." "=" "5/6)#
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("Putting it all together")#
#3 + 5/6 = 3+0.83333... = 3.83333....#
Rounded to 4 decimal places gives
#3.8333#