The school bought 130 boxes of chalk and used 8 boxes every week for 5 weeks. How many boxes are left? ?
学校买来130盒粉笔，每星期用8盒，用了5个星期，还剩多少盒？？
<gadget id="calculator">8 * 5</gadget>
<output>40</output>

<gadget id="calculator">130 - 40</gadget>
<output>90</output>

<result>90</result>