There are 756 poplars and willows planted in a primary school. The ratio of the number of poplars and willows planted is 4:5. How many poplars are planted?
某小学植杨树和柳树共756棵，种的杨树和柳树的棵数的比是4：5，种杨树多少棵？
<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">756 * (4/9)</gadget>
<output>336</output>

<result>336</result>