2025年小学同步练习册五年级数学上册人教版山东专版人民教育出版社第34页答案
一、不计算,用发现的规律直接写出下面几题的积。
1. $6×7 = 42$
2. $99.99×1 = 99.99$
$6.6×6.7 = 44.22$
$99.99×2 = 199.98$
$6.66×66.7 = 444.222$
$99.99×3 = 299.97$
$6.666×666.7 = $
$99.99×4 = $

答案

1. 4444.2222 2. 399.96
二、用计算器计算下面各题,发现其规律。
1. $4×9 = $
2. $5×9 = $
$44×99 = $
$55×99 = $
$444×999 = $
$555×999 = $
$4444×9999 = $
$5555×9999 = $
3. $6×9 = $
4. $7×9 = $
$66×99 = $
$77×99 = $
$666×999 = $
$777×999 = $
$6666×9999 = $
$7777×9999 = $

答案

1. 36 4356 443556 44435556 2. 45 5445 554445 55544445 3. 54 6534 665334 66653334 4. 63 7623 776223 77762223

解析

1. $4×9 = 36$
$44×99 = 4356$
$444×999 = 443556$
$4444×9999 = 44435556$
2. $5×9 = 45$
$55×99 = 5445$
$555×999 = 554445$
$5555×9999 = 55544445$
3. $6×9 = 54$
$66×99 = 6534$
$666×999 = 665334$
$6666×9999 = 66653334$
4. $7×9 = 63$
$77×99 = 7623$
$777×999 = 776223$
$7777×9999 = 77762223$
三、不计算,运用规律直接写出得数。
$9×9 + 9 = 90$
$99×99 + 99 = 9900$
$999×999 + 999 = $
$9999×9999 + 9999 = $
$99999×99999 + 99999 = $
$999999×999999 + 999999 = $
$9999999×9999999 + 9999999 = $
$99999999×99999999 + 99999999 = $
$999999999×999999999 + 999999999 = $

答案

999000 99990000 9999900000 999999000000 99999990000000 9999999900000000 999999999000000000