P5 Maths (10marks)

1.
4 3/8 * 2 2/15
= 35/8* 32/15
= 7/1 * 4/3 (約簡)
= 28/3
= 9 1/3

2.
6 3/7 ÷ 5/14
= 45/7 * 14/5
= 9/1 * 2/1
= 18

3.
1 3/8 ÷8 1/4 ÷ 6/7
= 11/8÷ 33/4 ÷ 6/7
= 11/8 * 4/33 * 7/6
= 1/2 * 1/3 * 7/6
= 7/36

4
60人,男佔5/12
60 * 5/12
= 5 * 5/1 (約簡)
= 25
男人 25, 女人 35

5.
50粒波子放入40cm長,20cm闊的瓶,水位由8cm升至10cm,求每粒波子的cm3
50粒波子的體積 = 水多出了的體積
= (20*40) * (10-8)
= 800 * 2
= 1600 cm3

每粒波子體積 = 1600/50
= 32cm3

4 3/8 * 2 2/15
=(4*8+3)/8 * (2*15+2)/15
=35/8 * 32/15
=1120 / 120
=9 40/120
=9 1/3

6 3/7 ÷ 5/14
=(6*7+3)/7 ÷ 5/14
=45/7 ÷5/14
=45/7 * 14/5
=9*2
=18

1 3/8 ÷ 8 1/4 ÷ 6/7
=(1*8+3)/8 ÷(8*4+1)/4 ÷ 6/7
=11/8 ÷ 33/4 ÷6/7
=11/8 *4/33 * 7/6
=(1*7)/(2*3*6)
=7/36

男生的人數
= 60 * 5/12
25人

每粒波子的cm3
=40*20*(10-8) ÷50
=1600 ÷50
=32cm3

1. 4 3/8 * 2 2/15
= 35/8 * 32/15
= 7/3
= 2 1/3

2. 6 3/7 ÷ 5/14
= 45/7 * 14/5
= 9 * 2
=18

3. 1 3/8 ÷ 8 1/4 ÷ 6/7
= 11/8 * 4/33 * 7/6
= 7/36

4. 60 * 5/12
= 25人

5. [ 40cm * 20cm * ( 10 - 8 )cm ] ÷ 50
= 40 * 20 * 2 cm3 ÷ 50
= 1600 cm3 ÷ 50
= 32cm3

2007-06-08 10:04:50 補充：
改正1. 4 3/8 * 2 2/15 = 35/8 * 32/15 = 28/3 = 9 1/3對不起

1.4 3/8 * 2 2/15
=35/8 * 32/15
=7/1 * 4/3
=28/3
=9 1/3

2.6 3/7 ÷ 5/14
=45/7 ÷ 5/14
=45/7 * 14/5
=9/1 * 2/1
=18

3.1 3/8 ÷ 8 1/4 ÷ 6/7
=11/8 ÷ 33/4 ÷ 6/7
=11/8 * 4/33 * 7/6
=1/1 * 2/3 * 7/3
=14/9
=1 5/9

4.60 * 5/12
=5 * 5/1
=25(人)

5.(40 * 20 * 10 - 40 * 20 * 8) ÷ 50
=1600 ÷ 50
=32(cm3)

2007-06-08 10:00:45 補充：
Corr.3.1 3/8 ÷ 8 1/4 ÷ 6/7=11/8 ÷ 33/4 ÷ 6/7=11/8 * 4/33 * 7/6=1/2 * 1/3 * 7/6=7/36

4 3/8 X 2 2/15

= 35/8 X 32/15

= 7 X 4/3

= 28/3



6 3/7 ÷ 5/14

= 45/7 X 14/5

= 9 X 2

= 18




1 3/8 ÷ 8 1/4 ÷ 6/7

= 11/8 ÷ 33/4 X 7/6

= 11/8 X 4/33 X 7/6

= 1/2 X 1/3 X 7/6

= 7/36




60 人裏，男人人數佔了5/12

所以，男人人數

= 60 X 5/12

= 25(人)

女人人數

= 60 - 25

= 35(人)




50粒波子的總體積

= 水位「增加」的容量

= 40 X 20 X (10 - 8)

= 1600 cm³

所以，每粒波子的體積

= 1600 / 50

= 32 cm³