How to write eight ten-thousandths of thirty-five million in scientific notation?

Eight ten-thousandths = 8*(1/10,000) = 8/10⁴ = 8 x 10⁻⁴.
Thirty-five million = 35*(1,000,000) = 35 x 10⁶

Therefore eight ten-thousandths of thirty-five million is
(8 x 10⁻⁴) * (35 x 10⁶)
= 280 x 10⁶⁻⁴
= 280 x 10²
= (2.8 x 10²) * 10²
= 2.8 x 10⁴

 2.8 x 10⁴

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