人教版数学六年级上册《确定起跑线》课件

1、确定起跑线,男子100m决赛起跑的画面,男子100m比赛决赛终点冲刺的画面,男子400m决赛起跑的画面,男子400m比赛决赛终点冲刺的画面,终点位置相同,起跑位置不同,为什么100m比赛是在直道上进行起跑，而400m要在不同的位置上起跑呢,400米标准运动场一般有八条跑道，最里面的为第一道，依次为第二道，第三道，第四道，每条跑道有内外两条线组成，每条跑道的长度是指这条跑道中内侧线的长度,85.96m,72.6m,第一跑道,1.25m,1.25m,1.25m,直道的长度是85.96米，第一条圆形的 跑道的直径是72.6米，每条跑道宽1.25米,85.96m,72.6m,1.25m,1.25m,1

2、.25m,跑道一圈的长度=2条直道长度+一个圆的周长,注：取3.14159,85.96m,72.6m,第一道,直径,周长,全长,72.6m,72.63.14159228.08（m,85.962228.08=400（m,72.6,228.08,400,注：取3.14159,85.96m,72.6m,第一道,直径,周长,全长,72.6m,228.08m,400m,第二道,直径,周长,全长,72.61.251.25=75.1（m,75.13.14159235.93（m,85.962235.93=407.85（m,1.25m,1.25m,72.6,228.08,400,75.1,235.93,407.

3、85,注：取3.14159,85.96m,72.6m,第二道,直径,周长,全长,75.1m,235.93m,407.85m,第三道,直径,周长,全长,75.11.251.25=77.6（m,77.63.14159243.79（m,85.962243.79=415.71（m,1.25m,1.25m,75.1m,72.6,228.08,400,75.1,235.93,407.85,77.6,243.79,415.71,注：取3.14159,85.96m,72.6m,第三道,直径,周长,全长,77.6m,243.79m,415.71m,第四道,直径,周长,全长,77.61.251.25=80.1（m

4、,80.13.14159251.64（m,85.962251.64=423.56（m,1.25m,1.25m,77.6m,72.6,228.08,400,75.1,235.93,407.85,77.6,243.79,415.71,80.1,251.64,423.56,注：取3.14159,85.96m,72.6m,第四道,直径,周长,全长,80.1m,251.64m,423.56m,第五道,直径,周长,全长,80.11.251.25=82.6（m,82.63.14159259.50（m,85.962259.5=431.42（m,72.6,228.08,400,75.1,235.93,407.8

5、5,77.6,243.79,415.71,80.1,251.64,423.56,82.6,259.5,431.42,注：取3.14159,85.96m,72.6m,第五道,直径,周长,全长,82.6m,259.5m,431.42m,第六道,直径,周长,全长,82.61.251.25=85.1（m,85.13.14159267.35（m,85.962267.35=439.27（m,72.6,228.08,400,75.1,235.93,407.85,77.6,243.79,415.71,80.1,251.64,423.56,82.6,259.5,431.42,85.1,267.35,439.27

6、,注：取3.14159,85.96m,72.6m,第六道,直径,周长,全长,85.1m,267.35m,439.27m,第七道,直径,周长,全长,85.11.251.25=87.6（m,87.63.14159275.20（m,85.962275.2=447.12（m,72.6,228.08,400,75.1,235.93,407.85,77.6,243.79,415.71,80.1,251.64,423.56,82.6,259.5,431.42,85.1,267.35,439.27,87.6,275.2,447.12,注：取3.14159,85.96m,72.6m,第七道,直径,周长,全长,8

7、7.6m,275.2m,447.12m,第八道,直径,周长,全长,87.61.251.25=90.1（m,90.13.14159283.06（m,85.962283.06=454.98（m,72.6,228.08,400,75.1,235.93,407.85,77.6,243.79,415.71,80.1,251.64,423.56,82.6,259.5,431.42,85.1,267.35,439.27,87.6,275.2,447.12,90.1,283.06,454.98,注：取3.14159,各跑道的起跑线应该相差多少米,7.85m,7.86m,7.85,7.86,7.85,7.86,7.85,7.85,7.86,400米相邻跑道的起跑线相差,道宽2圆周率,所以，跑道之间的差距与直道无关,达标检测,123.14=6.28（米,1.223.147.54（米,1校园运动会的跑道宽比成人比赛的跑道宽要窄些，400米的跑步比赛，跑道宽为1米，你能帮裁判计算出相邻两条跑道的起跑线应该依次提前多少米吗？如果跑道宽是1.2米呢？（圆周率取3.14,2.下图是某小学操场的跑道，跑道外圈和内圈相差多少米？（两端各是半圆， 取3.14,323.14=18.84(米,1.小狗和小