10-9+8-7+6-5+4-3+2-1=how much.
10-9+8-7+6-5+4-3+2-1=多少．
<gadget id="calculator">10 - 9</gadget>
<output>1</output>

<gadget id="calculator">8 - 7</gadget>
<output>1</output>

<gadget id="calculator">6 - 5</gadget>
<output>1</output>

<gadget id="calculator">4 - 3</gadget>
<output>1</output>

<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">1 + 1 + 1 + 1 + 1</gadget>
<output>5</output>

<result>5</result>