120,000,000 grams is 120 Megagrams
Here, we want to make a conversion from grmas to Megagrams
Mathematically;
1,000,000 grams is 1 Megagram
so;
120,000,000 grams will be x megagram
Thus;
[tex]\begin{gathered} 1,000,000\text{ }\times\text{ x = 120,000,000 }\times\text{ 1} \\ \\ x\text{ = }\frac{120,000,000}{1,000,000} \\ \\ x\text{ = 120 Megagrams} \end{gathered}[/tex]