Evaluate Using Scientific Notation (2.810^-4)(7.710^9)

$(2.8 \cdot 10^{- 4}) (7.7 \cdot 10^{9})$

Group coefficients together and exponents together to multiply numbers in scientific notation.

$(2.8 \cdot 7.7) (10^{- 4} \cdot 10^{9})$

Multiply $2.8$ by $7.7$ .

$21.56 (10^{- 4} \cdot 10^{9})$

Multiply $10^{- 4}$ by $10^{9}$ by adding the exponents.

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$21.56 \cdot 10^{- 4 + 9}$

Add $- 4$ and $9$ .

$21.56 \cdot 10^{5}$

Write $21.56 \cdot 10^{5}$ in proper scientific notation.

$2.156 \cdot 10^{6}$

Evaluate Using Scientific Notation (2.8*10^-4)(7.7*10^9)