A school planned to invest 1.2 million yuan in the construction of a plastic playground, but actually used 900,000 yuan. How much was the savings?
某校建修塑胶操场计划投资120万元，实际用了90万元，节省了百分之几？
<gadget id="calculator">120 - 90</gadget>
<output>30</output>

<gadget id="calculator">30 / 120</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>