《2025年口算训练五年级数学上册人教版双色升级版》

1. 保留两位小数。
$3.282828\cdots\approx$
$5.234234\cdots\approx$
$18.444\cdots\approx$
$0.307307\cdots\approx$
$8.666\cdots\approx$
$2.333\cdots\approx$
$5.777\cdots\approx$
2. 用简便形式写小数。
$0.191919\cdots=$
$0.250250\cdots=$
$3.312312\cdots=$
$5.9343434\cdots=$
$2.333\cdots=$
$4.625625\cdots=$
$0.76927692\cdots=$
$0.666\cdots=$
$1.777\cdots=$
$6.332332\cdots=$
$0.010101\cdots=$
$7.2333\cdots=$

答案： 1. 3.28
5.23
18.44
0.31
8.67
2.33
5.78
2. $0.\dot{1}\dot{9}$
$0.\dot{2}5\dot{0}$
$3.\dot{3}1\dot{2}$
$5.9\dot{3}\dot{4}$
$2.\dot{3}$
$4.\dot{6}2\dot{5}$
$0.\dot{7}69\dot{2}$
$0.\dot{6}$
$1.\dot{7}$
$6.\dot{3}3\dot{2}$
$0.\dot{0}\dot{1}$
$7.2\dot{3}$

按规律直接写出积。
$11×11=121$
$11×12=132$
$11×13=143$
$11×14=$154
$11×15=$165
$11×16=$176
$11×17=$187
$11×18=$198
$11×19=$209
$111×111=12321$
$111×222=24642$
$111×333=$36963
$111×444=$49364
$111×555=$61605
$111×666=$73926
$111×777=$86347
$111×888=$98568

答案： $11×14=154$
$11×15=165$
$11×16=176$
$11×17=187$
$11×18=198$
$11×19=209$
$111×333=36963$
$111×444=49364$
$111×555=61605$
$111×666=73926$
$111×777=86347$
$111×888=98568$