Guangming Primary School has 1000 people from 2 grades to visit the Science and Technology Museum. Among them, girls in grade 5 accounted for 1/4 of the total number of visitors, and girls in grade 6 accounted for 40% of the total number of visitors. Please use one or two steps according to the conditions Or three-step calculation problem parallel calculation.
光明小学有2个年级共1000人到科技馆参观，其中，五年级女生占参观总人数的(1/4)，六年级女生占参观总人数的40%，请你根据条件题意一个两步或三步计算的问题并列式计算．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1_000 * (2/5)</gadget>
<output>400</output>

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

<gadget id="calculator">1_000 * (1/4)</gadget>
<output>250</output>

<gadget id="calculator">400 - 250</gadget>
<output>150</output>

<result>150</result>