The sixth grade students played a pitching game, throwing red and yellow balls into a small iron basket 5 meters away. Each red ball was scored 7 points, and each yellow ball was scored 5 points. Li Hao scored 58 points in total. How many red balls did he score?
六年级同学做投球游戏，把红、黄两种颜色的球投进5米外的小铁筐里，每投进一个红球得7分，每投进一个黄球得5分．李浩一共得58分，他投进了多少个红球？
<gadget id="calculator">28 / 7</gadget>
<output>4</output>

<result>4</result>