The sum of three numbers is 26.7. The first number is 7.9, which is 0.6 less than the third number. What is the second number?
三个数的和是26.7，其中第一个数是7.9，比第三个数少0.6，则第二个数是多少．
<gadget id="calculator">7.9 + 0.6</gadget>
<output>8.5</output>

<gadget id="calculator">26.7 - 7.9 - 8.5</gadget>
<output>10.3</output>

<result>10.3</result>