Question

express this number in scientific notation. 31 billion

Explanation:

Step1: Recall the value of a billion

A billion is \(10^9\), so 31 billion is \(31\times10^9\).

Step2: Convert to scientific notation

Scientific notation is in the form \(a\times10^n\) where \(1\leq a<10\). We rewrite 31 as \(3.1\times10^1\), so \(31\times10^9 = 3.1\times10^1\times10^9\). Using the rule of exponents \(a^m\times a^n=a^{m + n}\), we get \(3.1\times10^{1 + 9}=3.1\times10^{10}\).

Answer:

\(3.1\times10^{10}\)