The school brought a pile of sand, (2/5) tons were used to build the walls, and (3/8) tons were used to repair the sports field. At this time, there is still (1/4) tons left. How many tons is this pile of sand originally?
学校运来一堆沙子，砌墙用去(2/5)吨，修运动场用去(3/8)吨，此时还剩(1/4)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 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(2/5) + (3/8) + (1/4)</gadget>
<output>41/40 = around 1.025</output>

<result>41/40 = around 1.025</result>