Question

MULTIPLYING AND DIVIDING IN SCIENTIFIC NOTATION

Find the product or quotient. Write your answer in scientific notation.

$(7.2\times {10}^{-1})\times (4\times {10}^{-7})$

Answer 1

Find product

$(7.2\times {10}^{-1})\times (4\times {10}^{-7})$

$=(7.2\times 4)\times ({10}^{-1}\times {10}^{-7})$ (Multiplying digits and powers simultaneously)

$=(28.8)\times {10}^{-1+(-7)}$ (Using exponent ${\mathrm{a}}^{\mathrm{m}}\times {\mathrm{a}}^{\mathrm{n}}={\mathrm{a}}^{\mathrm{m}+\mathrm{n}}$)

$=2.88\times {10}^1\times {10}^{-8}$

$=2.88\times {10}^{1-8}$

$=2.88\times {10}^{-7}$

Hence, the product (in scientific notation) is $2.88\times {10}^{-7}$ .