人教版小学三年级《24时计时法》课件

24时计时法,年、月、日,联系生活：,问题：小红的一天是怎样度过的，她都做了什么事情？请你用“早上几时、中午几时、晚上几时，小红在做什么”这样的句式说说。,操作活动：,（2）全班交流。,活动：拿出钟表拨时针，说一说。,要求：（1）2人合作，边拨边说说自己的发现。,（3）回答问题。,（1）从0时到中午12时，经过了（）小时。,（2）从中午12时再到0时，又经过了（）小时。,（3）一天是（）小时。,经过一天，钟面上的时针转了（）圈。,12,12,2,24,12,9,1,8,7,6,4,3,2,5,11,10,0,0,半夜12时也叫0时,12,9,1,8,7,6,4,3,2,5,11,10,0,1,2,3,4,5,6,7,8,9,10,11,12,12,9,1,8,7,6,4,3,2,5,11,10,0,1,2,3,4,5,6,7,8,9,10,11,12,12,9,1,8,7,6,4,3,2,5,11,10,13,0,1,2,3,4,5,6,7,8,9,10,11,12,13,12,9,1,8,7,6,4,3,2,5,13,11,10,14,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,12,9,1,8,7,6,4,3,2,5,13,11,10,14,15,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,15,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,15,17,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,15,18,17,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,20,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,20,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,21,20,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,20,21,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,21,22,20,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,20,21,22,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,23,21,22,20,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,20,21,22,23,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,24,23,21,22,20,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,20,21,22,23,24,认真观察：,问题：钟面上有红色、蓝色两圈，如果把钟面上时针走过的一天的时间展开，会是什么样子呢？,转化计时法：,问题：上午9时用24时计时法是几时？下午5时用24时计时法是几时？晚上9时呢？说一说你是怎么知道的。,第一圈,第二圈,1、用24时计时法表示出下面的时刻,2、17时是下午几时？23时是晚上几时？,下午3时上午10时晚上9时下午6时晚上10时下午2时,15时,10时,21时,18时,22时,14时,下午5时,晚上11时,3、用普通计时法表示下面的时刻,6时12时时30分24时16时18时45分,早上6时,中午12时,上午9时30分,下午6时45分,下午4时,深夜12时（0时）,4、这是一个新设邮筒，每天取3次信，早上8时30分第一次取信，以后每隔4小时取一次信。请标出每次取信的时间。,取信时间,第一次：,第二次：,第三次：,8：30,12：30,16：30,你是怎样想的？说说你的想法？,碧水小学2016年夏季作息时间表,通过今天的学习，你有什么收获?,同学们：今天的学习开心吗？,今