10-1.2+5-3.4+3-5.6+2-7.8=how much.
10-1.2+5-3.4+3-5.6+2-7.8=多少．
<gadget id="calculator">10 - 1.2</gadget>
<output>8.8</output>

<gadget id="calculator">5 - 3.4</gadget>
<output>1.6</output>

<gadget id="calculator">3 - 5.6</gadget>
<output>-2.6</output>

<gadget id="calculator">2 - 7.8</gadget>
<output>-5.8</output>

<gadget id="calculator">8.8 + 1.6 + (-2.6) + (-5.8)</gadget>
<output>2</output>

<result>2</result>