In the formula mouth/7*4/6+66=4100, what number should be filled in at the mouth?
在算式口/7*4/6+66=4100中，口处应填写的数是多少？
<gadget id="calculator">4_100 - 66</gadget>
<output>4_034</output>

<gadget id="calculator">6 / 4</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">4_034 * (3/2) * 7</gadget>
<output>42_357</output>

<result>42_357</result>