Question

what is 0.122 in scientific notation? 1.22x10^-2 1.22x10^-1 1.22x10^0 1.22x10^-3 what is 2.99x10^8 as a decimal? 2,990,000 2,990,000,000 299,000,000 29,900,000

Explanation:

Step1: Recall scientific - notation rule

Scientific notation is of the form $a\times10^{n}$, where $1\leq|a|\lt10$ and $n$ is an integer. For $0.122$, move the decimal point one place to the right to get $a = 1.22$. Since we moved the decimal point one place to the right, $n=- 1$. So $0.122 = 1.22\times10^{-1}$.

Step2: Recall converting scientific - notation to decimal

For $2.99\times10^{8}$, the exponent of 10 is 8. This means we move the decimal point 8 places to the right. Starting with 2.99, we get 299000000.

Answer:

1. B. $1.22\times10^{-1}$
2. B. 2,990,000,000