Answer:
10

Explanation:
We know that a biologist counted 10,000 migrating monarch butterflies and we are to write this number of butterflies as a power of 10.
Numbers such as 10, 100, 1000, 10000 can be expressed as a power of 10 denoted by 
 where the power
 where the power 
 is the number of zeros in that number.
 is the number of zeros in that number.
So we can write 10,000 as:
