人教版三年级下册数学24时计时法(公开课).ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2020/12/18,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2020/12/18,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2020/12/18,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2020/12/18,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2020/12/18,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2020/12/18,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2020/12/18,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2020/12/18,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2020/12/18,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2020/12/18,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2020/12/18,*,24,时计时法,2020/12/18,1,早晨,8:00,2020/12/18,2,中午,12:00,2020/12/18,3,2020/12/18,4,开馆时间,8,：,3016,：,30,16,：,30,是几时？,科技馆,2020/12/18,5,新的一天都是从（）时开始的，这个时刻也叫做（）或（）。,深夜,12,24,时,0,时,我来学一学,2020/12/18,6,一天的时间,在一日中，钟表上 的,时针正好走,（）,2,圈,共,24,小时。所以，,经常采用从,0,时到,24,时的计时,法，通常叫做,(),24,时计时法。,（）,2020/12/18,7,0,：,00,1,：,00,2,：,00,3,：,00,4,：,00,5,：,00,6,：,00,7,：,00,8,：,00,9,：,00,10,：,00,11,：,00,12,：,00,新的一天开始啦,2020/12/18,8,12,9,1,8,7,6,4,3,2,5,11,10,13,0,1,2,3,4,5,6,7,8,9,10,11,12,13,2020/12/18,9,12,9,1,8,7,6,4,3,2,5,13,11,10,14,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,2020/12/18,10,12,9,1,8,7,6,4,3,2,5,13,11,10,14,15,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,2020/12/18,11,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,15,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,2020/12/18,12,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,15,17,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,2020/12/18,13,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,15,18,17,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,2020/12/18,14,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,2020/12/18,15,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,20,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,20,2020/12/18,16,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,21,20,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,20,21,2020/12/18,17,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,21,22,20,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,20,21,22,2020/12/18,18,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,23,21,22,20,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,20,21,22,23,2020/12/18,19,12,9,1,8,7,6,4,3,2,5,13,11,10,14,16,19,15,18,17,24,23,21,22,20,0,1,2,3,4,5,6,7,8,10,11,12,13,14,15,9,16,17,18,19,20,21,22,23,24,2020/12/18,20,1,时,2,时,3,时,4,时,5,时,6,时,7,时,8,时,9,时,10,时,11,时,12,时,2020/12/18,21,13,时,14,时,15,时,16,时,17,时,18,时,19,时,20,时,21,时,22,时,23,时,24,时,2020/12/18,22,13,时,15,时,16,时,17,时,18,时,19,时,20,时,21,时,22,时,23,时,24,时,14,时,或,0,时,2020/12/18,23,第一圈,第二圈,加,12,不变,2020/12/18,24,说一说 想一想,谁知道怎样进行,12,时计时法和,24,时记时法的相互转换？,我能行,2020/12/18,25,24时计时法与普通计时法之间进行转换的方法：,在中午12时之前，普通计时法与24时计时法中的数字是相同的；在中午之后，普通计时法换成24时计时法只要把相对应的几时加上12就可以了，相反把24时计时法换成普通计时法只要把超过12时的相应的时间减去12就可以了，用普通计时法还要注意加上“上午”或“中午”、“晚上”等汉字加以说明。,我会记,2020/12/18,26,24,时计时法表示法,上午,9,时,9,时,下午,1,时,1+12=13,，就是,13,时,晚上,9,时,9+12=21,，就是,21,时,我来试一试,2020/12/18,27,用,24,时计时法表示下面的时刻。,下午,6,时 （）,晚上,12,时 （）,上午,8,时 （）,晚上,9,：,30,（）,凌晨,5,点 （）,傍晚,7,：,00,（）,18,：,00,24,：,00,或,0,：,00,8,：,00,21,：,30,5,：,00,19,：,00,我来练一练,2020/12/18,28,用普通计时法表示下面的时刻。,6,时,12,时,10,时,30,分,23,时,16,时,20,时,45,分,早上,6,：,00,中午,12,：,00,上午,10,：,30,晚上,11,：,00,下午,4,：,00,晚上,8,：,45,2020/12/18,29,500,1300,1820,2020/12/18,30,请同学们说 一说我们这一节课学习了哪些内容？,小结,我来说一说,2020/12/18,31,老师赠言：一寸光阴一寸金，,寸金难买寸光阴,少壮不努力,老大徒伤悲,珍惜时间 珍爱生命,2020/12/18,32,