I need to know how to convert 11390cm cubed into metres cubed

Let us see how to do the conversion, with a little more care.
1 m=100 cm
1cm =1/100 m =0.01
(1cm)*(1cm)*(1 cm)=1 cm^3
In terms of m^3
1 cm^3 =(0.01 m)*(0.01 m)*(0.01 m)=(0.01)^3 m^3= 1/1 000 000 m^3
There are 1000 000 (1 million) cm^3 in 1 m^3
Thus
11 390 cm^3= 11 390 /1 000 000=0.01139 m^3

Your calculator may or may not have a program for unit conversion, but the best method is to understand the metric system so you can do these conversions without a calculator. A meter is the same as 100 centimeters, so divide 11390 by 100 to get 113.90 m^3.

Rather than relying on a calculator, I highly recommend taking the time to practice metric conversions. It is very common for high school and even college professors to try and trick you by, for example, requesting the answer in centimeters when the question is in meters.