WEBVTT
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The planet Mercury is roughly two-fifth of the size of Earth.
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Write the fraction as a decimal.
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Our job here is to take the number two-fifths and write it as a decimal number.
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What we know about place value is the number to the left of the decimal is ones place and the number to the right of the decimal is tenths place.
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The fraction two-fifths does not have a whole number.
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This means there’s a zero in the ones place.
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Now we need to figure out how to write two-fifths as a tenth.
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The tenth decimal place can be written as a fraction out of 10.
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Is there a way to take two-fifths and turn it into a fraction out of 10?
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We know that five times two equals 10.
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We also know that if you multiply the denominator by something, you have to multiply the numerator by the same amount.
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Two times two equals four.
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Two-fifths equals four 10ths.
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And four 10ths can be written in the tenths place.
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Two-fifths written as a decimal equals four 10ths, 0.4.