\(99 \frac {1}{97}× \frac {97}{98}\)
\( \frac {1}{6}+ \frac {1}{12}+ \frac {1}{20}+ \frac {1}{30}+ \frac {1}{42}+ \frac {1}{56}+ \frac {1}{72}\)

【考点】计算,分数的四则运算

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