The road construction team built a 15-kilometer-long road. They built 3.7 kilometers in the first week and 4.6 kilometers in the second week. How many kilometers are left to be repaired?
修路队修一条长15千米的路，第一周修了3.7千米，第二周修了4.6千米，还剩多少千米没有修？
<gadget id="calculator">3.7 + 4.6</gadget>
<output>8.3</output>

<gadget id="calculator">15 - 8.3</gadget>
<output>6.7</output>

<result>6.7</result>