计算。

3/7+4/5=    5/12+5/8=     7/9+6/7=  1-2/7-3/7=  1/4+1/6+3/4=  1/2-1/6=

计算下面各题． (2)/(9)×(3)/(5)(6)/(7)×(7)/(9)(5)/(8)×(4)/(15)(9)/(20)×(5)/(21)(6)/(5)×(

[主观题]计算。7/8-5/6=2/9+1/2=6/7-2/3=3/10+1/4=3/7+1/9=1/3-1/5=1/6+1/4=5/7-1/5=

计算：(1)/(3)×(3)/(5)+1(5)/(7)-(5)/(9)×(5)/(7)1-(5)/(7)×(21)/(25)(1)/(2)+(5)/(4)×(4

(1)(2)(3)(4)(5)(6)(7)(8)(9)(1)(2)(3)(4)(5)(6)(7)(8)(9)

(1)(2)①②③④⑤⑥⑦⑧⑨⑩(3)(4)(5)①②③④⑤⑥⑦⑧⑨⑩(6)(7)①②③④⑤⑥⑦⑧⑨⑩(8)(9)①②③④⑤(1)(2)①②③④⑤⑥⑦⑧⑨⑩(3

1 2 3 4 5 6 7 8 9 10

计算：（1）23×（-5）-（-3）÷(3)/(128)；（2）-7×（-3）×（-0.5）+（-12）×（-2.6）；（3）（1(3)/(4)-(7)/(8)

三、找规律填数字-|||-6 7 8 !-|||-6 8-|||-3 5 9-|||-8 6 5-|||-3 7-|||-1 2 4 5

[单选题]6，7，5，8，4，9，( )A．5 B.10 C.3 D.4

[单选题]6，7，5，8，4，9，（　　）。A.5B.10C.3D.4