A certain class of students donated 640 yuan to the out-of-school children. The ratio of the money donated by girls to the money donated by boys is 5:3. According to the above conditions, Wang Ming got the following four conclusions. The wrong one is how much less boys donated than girls.
某班学生为失学儿童捐款640元，女生捐的钱与男生捐的钱之比为5：3，王明根据上面的条件，得到下面四个结论，其中错误的是男生比女生少捐多少
<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>