Wang Fang brought 15.6 yuan, bought a pen and spent 6.4 yuan, bought a bottle of ink and spent 3.6 yuan, how much money is left?
王芳带了15.6元钱，买一支钢笔用去6.4元，买一瓶墨水用去3.6元，还剩下多少元？
<gadget id="calculator">6.4 + 3.6</gadget>
<output>10</output>

<gadget id="calculator">15.6 - 10</gadget>
<output>5.6</output>

<result>5.6</result>