Describe how an increase in the carbon dioxide concentration can lead to global warming

The sun radiates and these rays enter our atmosphere. If there is a lot of carbon dioxide, the rays and radiation are prevented from leaving the the atmosphere, which means that the heat and energy stay inside and heat the planet more and more, which leads to global warming.

Fraction division is basically multiplication of a reciprocal.

For example (1/4)/(1/8) = (1/4)x(8/1)=2

Multiplication of the answer and the piece that divides (in this case 2 x 1/8), you should get the piece that is being divided (in this case 1/4). If that is correct, then your division is correct.