Calculation: 55*66+66*77+77*88+88*99.
计算：55*66+66*77+77*88+88*99．
<gadget id="calculator">11 * 11</gadget>
<output>121</output>

<gadget id="calculator">9 * 8</gadget>
<output>72</output>

<gadget id="calculator">8 * 7</gadget>
<output>56</output>

<gadget id="calculator">7 * 6</gadget>
<output>42</output>

<gadget id="calculator">6 * 5</gadget>
<output>30</output>

<gadget id="calculator">72 + 56 + 42 + 30</gadget>
<output>200</output>

<gadget id="calculator">121 * 200</gadget>
<output>24_200</output>

<result>24_200</result>