Glucose powder and water are used to prepare glucose injection, the mass ratio of glucose powder and water is 1:9, and there are 4.5 kg of glucose powder, how many kg of water need to be added?
用葡萄糖粉和水配制葡萄糖注射液，葡萄糖粉和水的质量比是1：9，现有4.5千克葡萄糖粉，需要加水多少千克？
<gadget id="calculator">4.5 * 9</gadget>
<output>40.5</output>

<result>40.5</result>