280 is 80 less than 5 times a number. Find this number. (solution by equation)
280比一个数的5倍少80，求这个数．(用方程解)
<gadget id="calculator">80 + 280</gadget>
<output>360</output>

<gadget id="calculator">360 / 5</gadget>
<output>72</output>

<result>72</result>