Xiao Ming miscalculated 5*(a+3) as 5*a+3, and the result was much less than the correct number
小明把5*(a+3)，错算成5*a+3，得到的结果比正确得数少多少
<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<gadget id="calculator">15 - 3</gadget>
<output>12</output>

<result>12</result>