Answer:
5.806 × 10³
Explanation:
Put a decimal point to the right of the left-most digit: 5.806. Now multiply by the place value of that digit.
5.806 × 10³
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The 5 is in the "thousands" place. Of course a "thousand" is 1000 = 10·10·10 = 10³. The place value multiplier (1000 or 10³) is written using the exponent when we write scientific notation.