The school expanded the school building, and the actual investment was 4.2 million yuan, which was (1/3) less than the original plan, and how many yuan was saved.
学校扩建校舍，实际投资420万元，比原计划节省(1/3)，节省了多少万元．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">420 / (2/3)</gadget>
<output>630</output>

<gadget id="calculator">630 - 420</gadget>
<output>210</output>

<result>210</result>