6下南一數學

[(7/10) - (2/3)] ÷ 0.64
= [(21/30) - (20/30)] ÷ (64/100)
= (1/30) x (25/16)
= 5/96


=====
(4又1/3) x 0.375 - (3/5) x 0.375
= (13/3) x (375/1000) - (3/5) x (375/1000)
= (13/3) x (3/8) - (3/5) x (3/8)
= (13/8) - (9/40)
= (65/40) - (9/40)
= 56/40
= 1.4


=====
20 + (5又1/3) ÷ (0.2)
= 20 + (16/3) ÷ (2/10)
= 20 + (16/3) x 5
= 20 + (80/3)
= (60/3) + (80/3)
= 140/3
= 46又2/3


=====
3.13 - (1/8) + 0.2 + (2/3)
= (313/100) - (1/8) + (1/5) + (2/3)
= (1878/600) - (75/600) + (120/600) + (400/600)
= 2323/600
= 3又523/600


=====
(3/4) x (5.69 - 3.29)
= (3/4) x (2.4)
= 1.8


=====
6.4 x (3/8) + 0.28 x (1/4)
= 2.4 + 0.07
= 2.47


=====
16.4 ÷ (4/7) + (2/5) x 3.5
= 16.4 x (7/4) + 1.4
= 28.7 + 1.4
= 30.1

(1) 5/96

(2) 7/5

(3) 140/3 or 46又2/3

(4) 1.305

(5) 9/5

(6) 31/10

(7) 301/10