The original price of a microwave oven is 840 yuan. The price has been increased (3/10) and then reduced (1/7). How much is the price of this microwave oven now?
一台微波炉原价840元，提价(3/10)后又降价(1/7)，现在这台微波炉的售价是多少元？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 + (3/10)</gadget>
<output>13/10 = around 1.3</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 - (1/7)</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">840 * (13/10) * (6/7)</gadget>
<output>936</output>

<result>936</result>