The first group has 6 male students and 4 female students. It is known that the average height of the male students is 4 cm higher than the average height of the female students. When Xiao Ming calculated the average height of the first group of students, he divided the sum of the average heights of the male and female students by 2 to obtain the result. Let me ask: Is the average height of the whole group calculated by Xiao Ming higher or lower than the correct average height? How many centimeters is the difference?
第一小组有6个男同学，4个女同学，已知男同学的平均身高比女同学的平均身高高4厘米．小明在计算第一小组同学的平均身高时用男同学和女同学的平均身高的和去除以2求得．试问：小明这样求出的全组平均身高比正确的平均身高数高还是低？相差多少厘米？
<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">6 / 10</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">4 * (3/5)</gadget>
<output>12/5 = around 2.4</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">(12/5) - 2</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>