Question

.
$( 4.9 \times 10 ^{ - 3} )(4 \times 10 ^{ - 2} )$

Answer 1

$(4.9 \times 10 ^{ - 3} )(4 \times 10 ^{ - 2}) = \\ = 4.9 \times 4 \times {10}^{ - 3} \times {10}^{ - 2} = \\ = 19.6 \times {10}^{ - 5} = 1.96 \times {10}^ { - 4}$