Add brackets to make both sides of the equal sign equal: 86-48/8-5=70, 90-72/9+3=79.
添上括号，使等号两边相等：86-48/8-5=70,90-72/9+3=79．
<gadget id="calculator">72 / 9</gadget>
<output>8</output>

<gadget id="calculator">8 + 3</gadget>
<output>11</output>

<gadget id="calculator">90 - 11</gadget>
<output>79</output>

<result>79</result>