To answer this question, you need to know the gravity power used for this equation. Let assume the gravity is 9.8N/kg. Then to find the mass, you need to multiply the weight with gravitational acceleration. The equation would be:
mass= weight x gravity
mass= 610mg x 10^-6 kg/mg x 9.8N/kg= 5978 x 10^-6= 5.978 x 10^-3
