三年级奥数-速算与巧算：乘法与除法

【例1】

121×5×2                     ② 17×4×25                 ③ 125×19×8

④24×25                        ⑤125×72                    ⑥16×16×25×125

巩固练习1：

125×23×8                        5×37×20                    32×25×125

【例2】

1526×9                     ② 123×99                     ③ 2004×25

巩固练习2：

        31×99                        378×9                        808×125

【例3】

145×11                 ② 56×11                 ③ 2222×11                ④2456×11

巩固练习3：

37×11                    78×11                    333×11                    3245×11

【例4】

1225÷9÷5                        ② （81 + 72）÷9 

2 （2046-1059-735）÷3            ④ 211÷50 + ÷50

巩固练习4：

450÷2÷5                （70+56）÷7            （2000-650-75）÷5            173÷30 + 427÷30

【例5】

1136×5÷8            ②125×(16÷10)                ③4032÷(8×9)                ④2560÷(10÷4)

⑤527×15÷5            ⑥2460÷5÷2                ⑦(54×24) ÷(9×4)

巩固练习5：

149×2÷7                ②250×(4÷10)                ③315÷(3×7)                ④1000÷(10÷4)

⑤25×32÷8                ⑥2300÷25÷4                ⑦(24×63) ÷(3×7)

二、速算与巧算：加法与减法（练习题）

练习一、

 4×73×25                            2×17×50                            8×13×125        

5×25××125                        625×32                            625×16

120×9                                387×99                            ×999

34×11×11                            555×11                                503×11

（497-210）÷7                        3÷10 + 17÷10                        (1000-688-136)÷8

2352÷（7×8）                        1200×（4÷12）                        1250÷（10÷8）  

3000×800÷400                636×35÷7

练习二、     16×125                    25×33×4                            88×125

625×3×32                            5×32                                8×250

83×9                                 71×99                                29×99

257×999                            701×999                            66×9999

427×11                                24×11×11                            83×11

(54×24)÷(9×4)              (126×56)÷(7×18) 

(128+1088)÷8            (1040-324+528)÷4        (182+325)÷13 

(2046-1059-735)÷3                 2460÷5÷2            527×15÷5

练习三、

23×25×12                            3×50×20                        24×7×125

234×99                            101×99                        57×99

93×11                                323×11                            456×11

313×11                                7777×11                        915×11

1125÷125                775÷25                        26÷25 + 40÷25 + 34÷25        

4032÷(8×9)                        125×(16÷10)        2560÷(10÷4)    

2352÷(7×8)                      2275÷13÷5                    1250÷(10÷8)