"mega-" = one million, so 1 megawatt = 1 000 000 watts. So 10 mW = 10 000 000 W.
1 mega-watt = 1,000,000 watts 1000 x 1,000,000 = 1,000,000,000 or one billion watts 1000 mega-watts also = 1 giga-watts
1 mega watt is 1,000,000 watts
One Billion
1 MW = 1000 kW, thus 1 kW = 0.001 MW