There's something in the Quran that I don't understand properly. They are from Surah Fussilat (41) verses 9 to 12:

*Say, "Do you indeed disbelieve in He who created the earth in two days and attribute to Him equals? That is the Lord of the worlds."*

*And He placed on the earth firmly set mountains over its surface, and He blessed it and determined therein its [creatures'] sustenance in four days without distinction - for [the information] of those who ask.*

*Then He directed Himself to the heaven while it was smoke and said to it and to the earth, "Come [into being], willingly or by compulsion." They said, "We have come willingly."*

*And He completed them as seven heavens within two days and inspired in each heaven its command. And We adorned the nearest heaven with lamps and as protection. That is the determination of the Exalted in Might, the Knowing.*

-Quran 41:9-12

It's saying that the earth was created in 2 days and the mountains were created in 4 days. So in total, that's 6 days for the earth. But in the last verse, it says the universe was created in 2 days. Why did the creation of earth take more time than the creation of the universe? It looks like it contradicts science. The earth is much much smaller than the universe. Can someone please give me the explanation for this? 

Thank you.