o={0,0,0};
u={1,2,3};
v={4,5,6};

Manipulate[Show[
Graphics3D[
{{Red,Arrow[{o,u}]},{Blue,Arrow[{o,v}]},{Green,Arrow[{o,t Cross[u,v]}]}}
],Ticks->False,PlotRange->{{-3,6},{-3,6},{-3,6}}],{{t,0,"Cross Product"},0,1}]