There are two ways to call another method function from the same class.
First, you can use a dot/period to access the method from the class variable. Second, you can simply call the function and pass the class object as an argument.
function r = roundOff(obj)
r = round([obj.Value],2);
function r = multiplyBy(obj,n)
r = [obj.Value] * n;
function d = doBoth(obj,k)
d = [obj.multiplyBy(k), roundOff(obj)];