分析:(1)根據(jù)比的基本性質(zhì)作答,即比的前項(xiàng)和后項(xiàng)同時(shí)乘或除以一個(gè)數(shù)(0除外)比值不變;
(2)用比的前項(xiàng)除以后項(xiàng)即可.
解答:解:(1)25:100,
=(25÷25):(100÷25),
=1:4;
25:100,
=25÷100,
=0.25,
(2)
:
,
=(
×
):(
×
),
=9:2,
:
,
=
÷
,
=
,
(3)0.9:0.36,
=(0.9×100):(0.36×100),
=90:36,
=(90÷18):(36÷18),
=5:2,
0.9:0.36,
=0.9÷0.36,
=2.5;
(4)
噸:375千克,
=250千克:375千克,
=250:375,
=(250÷125):(375÷125),
=2:3,
噸:375千克,
=250千克:375千克,
=250:375,
=250÷375,
=
.
比 |
25:100 |
: |
0.9:0.36 |
噸:375千克 |
最簡(jiǎn)整數(shù)比 |
1:4 |
9:2 |
5:2 |
2:3 |
比值 |
0.25 |
|
2.5 |
|
點(diǎn)評(píng):注意化簡(jiǎn)比的結(jié)果是一個(gè)比,它的前項(xiàng)和后項(xiàng)都是整數(shù),并且是互質(zhì)數(shù);而求比值的結(jié)果是一個(gè)商,可以是整數(shù),小數(shù)或分?jǐn)?shù).