Xiaojun weighed 32 kilograms with his schoolbag on his back, and 29 kilograms without his schoolbag. How many kilograms does the schoolbag weigh?
小军背着书包称得的重量是32千克，去掉书包称是29千克．书包重是多少千克
<gadget id="calculator">32 - 29</gadget>
<output>3</output>

<result>3</result>