Arthur has $200 in his wallet. He spends four-fifths of that. How much does he have left?
Arthur spent 4/5 * $200 = $
<gadget id="calculator">4/5*200</gadget>
<output>160</output>
160.
Thus he has $200 - $160 = $
<gadget id="calculator">200-160</gadget>
<output>40</output>
40 remaining.

<result>40</result>