At the end of the $$20th$$ century, the world population was approximately $$6.1\times 10^9$$ people. Express this population in usual form. How would you say this number in words?
In standard form of a number we put decimal after first digit and remaining power is written as power of $$10$$
Given at the end of the $$20^{th}$$ century, the world population was approx $$6.1\times 10^9$$, which is standard form
So,
Population of people in usual form $$=6.1\times 10^{9}=6100,000,000$$.
Thus, the population of the people is six thousand one hundred million.