Answer:
Silurian, Triassic, Jurassic, Tertiary
Step-by-step explanation:
Convert 6.64 so that is is 10[tex]^8[/tex]
So you'll have 0.664 × 10[tex]^8[/tex]
Then you can just order them from largest to smallest :)
If it doesn't make sense you can also convert the index notation (the powers with 10) into whole numbers so
2.08 × 10[tex]^8[/tex] = 2.08 × 100000000 = 208000000
and so on..
