精品北师大年夜版数学四年级下册《谁爬得快》课件.ppt

Who is faster? ;教学目标; A long time ago , there was a temple in the mountain. A monk was telling a story ,“ A long time ago, there was a temple in the mountain. A monk was telling a story, “A long time ago, there was a temple in the mountain. A monk was telling a story…””;……;123;从图中你能得到哪些数学信息?;循环小数;一个小数，从( )的某一位起，( )数字或者( )数字( )出现，这样的小数叫做循环小数。;填空 5.1487读作( ) 循环节是（ ）。;0.333…… 0.7272……;把下面是循环小数的用括号括起来，写成简便形式，并说说哪些小数的位数是无限的。;√;循环小数也可以根据需要取它的近似值。;（4）按要求写出下列各数的近似值。 ①0.10333……保留三位小数约是( )。 ②3.456456……精确到百分位约是( )。 ③12.86保留三位小数约是( )。;比较下面两个数的大小。 5.44 5.4 4.26 4.26 7.23 7.23;思考题：