The school brought a pile of sand, (2/5) tons were used to build the walls, (3/8) tons were used to repair the playground, and (1/10) tons remained. How many tons is this pile of sand?
学校运来一堆沙子，砌墙用去(2/5)吨，修运动场用去(3/8)吨，还剩(1/10)吨．这堆沙子原有多少吨？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(2/5) + (3/8) + (1/10)</gadget>
<output>7/8 = around 0.875</output>

<result>7/8 = around 0.875</result>