human skin has a thickness of about 5×10⁻³ meter. a grain of sand has a thickness of about 1×10⁻³ meter…

human skin has a thickness of about 5×10⁻³ meter. a grain of sand has a thickness of about 1×10⁻³ meter. about how many grains of sand would it take to match the thickness of human skin? grains of sand (1×10⁻³) human skin (5×10⁻³)
Answer
Answer:
5
Explanation:
Step1: Set up division formula
Let $n$ be the number of grains of sand. We use the formula $n=\frac{\text{Thickness of human skin}}{\text{Thickness of one - grain of sand}}$. So $n = \frac{5\times10^{- 3}}{1\times10^{-3}}$.
Step2: Simplify the fraction
When dividing numbers in scientific - notation with the same power of 10, we divide the coefficients. $\frac{5\times10^{-3}}{1\times10^{-3}}=\frac{5}{1}\times\frac{10^{-3}}{10^{-3}}$. Since $\frac{10^{-3}}{10^{-3}} = 1$, then $n = 5$.