Kev sib piv ntawm qhov sib piv thiab qhov sib piv
Hauv kev suav lej thiab lub neej txhua hnub, peb feem ntau piv ob yam: tus nqi piv rau qhov ntau, qhov deb piv rau lub sijhawm, lossis tus naj npawb ntawm cov tub ntxhais kawm txiv neej piv rau cov tub ntxhais kawm poj niam. Ob lub tswv yim feem ntau siv los tham txog cov kev sib piv no yog qhov sib piv thiab qhov sib piv. Txawm hais tias lawv zoo li zoo sib xws, thiab feem ntau yuam kev rau tib yam, lawv muaj lub luag haujlwm thiab kev siv sib txawv. Tsab xov xwm no piav qhia meej txog kev sib piv ntawm qhov sib piv thiab qhov sib piv, nrog rau cov piv txwv rau kev nkag siab yooj yim.
Nkag Siab Txog Qhov Sib Piv
Ib qho piv yog kev sib piv ntawm ob qho tib si zoo sib xws lossis sib piv tau. Nws qhia tias muaj pes tsawg zaus ib tus nqi raug piv rau lwm tus. Cov piv tuaj yeem sau ua ntau hom, piv txwv li:
– a : b (nyeem “a piv rau b”)
– ib/ib
– ua lus, piv txwv li “a piv rau b”
Piv txwv li, yog tias hauv ib chav kawm muaj 12 tus tub ntxhais kawm txiv neej thiab 18 tus ntxhais kawm poj niam, ces qhov sib piv ntawm cov txiv neej rau cov poj niam yog:
– 12:18
Qhov piv no tuaj yeem yooj yim dua los ntawm kev faib ob qho tib si los ntawm 6:
– 2:3
Qhov no txhais tau tias rau txhua 2 tus tub ntxhais kawm txiv neej, muaj 3 tus tub ntxhais kawm poj niam.
Cov yam ntxwv ntawm cov piv
1. Muab ob yam khoom sib piv (lossis ntau dua, tab sis feem ntau yog ob).
2. Yuav ua kom yooj yim zoo li ib feem.
3. Tsis yog ib txwm qhia tias "sib npaug"; qhov piv tsuas yog qhia txog kev sib piv xwb.
Nkag Siab Txog Qhov Feem Pua
Kev sib piv yog qhov sib npaug ntawm ob qho piv. Yog tias qhov piv ntawm A rau B zoo ib yam li qhov piv ntawm C rau D, ces qhov kev sib raug zoo no hu ua kev sib piv. Feem ntau nws yog sau ua:
– ib: b = c: d
los yog
– a/b = c/d
Piv txwv:
Yog tias 2/3 = 4/6, ces qhov no yog ib feem vim tias ob qho piv sib npaug.
Hauv lub neej tiag tiag, feem ntau siv cov piv txwv los daws cov teeb meem ntsig txog qhov ntsuas, cov zaub mov txawv, qhov ceev, tus nqi ntawm chav tsev, thiab lwm yam.
Cov yam ntxwv ntawm qhov sib piv
1. Ib txwm muaj ob qhov piv piv sib piv.
2. Qhia txog kev sib luag (tus nqi sib piv yog tib yam).
3. Feem ntau siv los nrhiav cov nqi tsis paub (cov hloov pauv).
Qhov Txawv Tseem Ceeb Ntawm Qhov Sib Piv Thiab Qhov Sib Piv
Txawm hais tias muaj feem cuam tshuam, qhov sib piv thiab qhov sib piv muaj qhov sib txawv tseem ceeb hauv kev txhais thiab kev ua haujlwm. Nov yog qhov sib piv tseem ceeb:
1. Lub ntsiab lus ntawm lub tswv yim
- Qhov sib piv: kev sib piv ntawm ob qhov ntau thiab tsawg.
- Kev sib piv: qhov sib npaug ntawm ob qho piv.
Qhov sib piv zoo li "sib piv," thaum qhov sib piv zoo li "sib piv ob qhov sib piv."
2. Daim Ntawv Qhia
- Qhov piv tsuas yog sau ua a: b.
– Qhov feem pua yog sau ua a: b = c: d lossis a/b = c/d.
3. Tujuan Penggunaan
- Cov piv txwv yog siv los qhia txog cov xwm txheej lossis cov qauv.
- Cov piv txwv yog siv los daws cov teeb meem uas xav tau kev sib npaug zos.
4. Txawm hais tias muaj kev sib luag los tsis muaj
- Qhov piv tsis xav tau kev sib npaug nrog lwm cov piv.
- Qhov sib piv yeej ib txwm qhia txog kev sib npaug ntawm ob qhov sib piv.
Piv txwv ntawm Cov Piv Txwv hauv Lub Neej Txhua Hnub
Piv txwv 1: Kev sib xyaw ua ke
Ib khob dej haus yog ua los ntawm cov kua txiv hmab thiab dej hauv qhov sib piv ntawm 1: 5. Qhov no txhais tau tias:
- txhua 1 feem kua txiv sib xyaw nrog 5 feem dej.
Nws yog ib qho piv vim nws tsuas yog qhia qhov sib piv ntawm cov khoom sib xyaw.
Piv txwv 2: Kev sib piv ntawm qhov deb thiab lub sijhawm
Ib tug neeg taug kev 120 km hauv 2 teev. Qhov piv ntawm qhov deb mus rau lub sijhawm yog:
– 120 : 2 = 60 : 1
Nws feem ntau cuam tshuam nrog kev ceev, tab sis qhov pib tseem ceeb yog qhov sib piv.
Piv txwv ntawm Cov Feem pua hauv Lub Neej Txhua Hnub
Piv txwv 1: Daim Ntawv Qhia Qhov Ntsuas
Daim ntawv qhia ntsuas 1:100.000 txhais tau tias 1 cm ntawm daim ntawv qhia = 100.000 cm hauv lub neej tiag tiag.
Yog tias qhov deb ntawm daim ntawv qhia yog 3 cm, qhov deb tiag tiag yog dab tsi?
Peb ua qhov sib piv:
– 1/100.000 = 3/x
Yog li ntawd:
– x = 3 × 100.000 = 300.000 cm = 3 km
Qhov no yog ib qho piv vim nws cuam tshuam nrog kev sib npaug ntawm ob qho piv thiab siv los nrhiav tus nqi ntawm x.
Piv txwv 2: Daim Ntawv Qhia Ua Noj
Ib daim ntawv qhia ua zaub mov rau 4 tus neeg yuav tsum siv 200 grams hmoov nplej. Yuav tsum siv pes tsawg grams rau 10 tus neeg?
Peb ua qhov sib piv:
– 200/4 = x/10
x = (200 × 10) / 4 = 500 grams
Qhov no yog ib qho piv txwv ntawm kev sib piv hauv kev sib piv rov qab lossis kev sib piv.
Kev sib raug zoo ntawm qhov sib piv thiab qhov sib piv
Qhov sib piv thiab qhov sib piv tsis yog sib cais. Qhov sib piv yeej yog tsim los ntawm lub tswv yim ntawm qhov sib piv. Yog tsis nkag siab txog qhov sib piv, nws yuav nyuaj rau nkag siab txog qhov sib piv. Txawm li cas los xij, muaj qhov sib piv ib leeg tsis txaus los tsim kom muaj qhov sib piv; peb xav tau lwm qhov sib npaug.
Qhov sib piv yog "cov khoom xyaw tseem ceeb", qhov sib piv yog "kev sib luag ntawm kev sib luag" ntawm ob qho kev sib piv.
Cov ntsiab lus:
- Qhov piv ntawm 2: 3 yog qhov sib piv.
Thaum peb hais tias 2:3 = 4:6, ces nws dhau los ua ib feem.
Yuav Ua Li Cas Xyuas Kom Paub Tseeb Tias Qhov Feem Puas Yog
Yuav kom paub tseeb tias a/b = c/d puas yog qhov sib piv raug, peb siv tau kev sib npaug ntawm cov lej sib npaug:
– ib × d = ib × c
Piv txwv:
– 2/3 = 4/6
Tshawb xyuas:
– 2 × 6 = 12
– 3 × 4 = 12
Vim tias lawv zoo ib yam, qhov sib piv yog qhov tseeb.
Yog tias cov txiaj ntsig tsis zoo ib yam, nws txhais tau tias ob qho piv tsis sib piv thiab tsis yog qhov sib piv raug.
Yuam Kev Feem Ntau Hauv Kev Nkag Siab Txog Qhov Sib Piv Thiab Qhov Sib Piv
1. Xav tias txhua qhov piv txwv tsis siv neeg yog cov piv txwv.
Tus piv tshiab dhau los ua ib qho piv thaum piv rau lwm cov piv sib npaug.
2. Tsis txhob ua kom qhov piv txwv yooj yim ua ntej.
Cov piv 12:18 thiab 2:3 yeej zoo ib yam, tab sis yog tias tsis ua kom yooj yim, lawv yuav ua rau tsis meej pem.
3. Tso qhov ntau tsis raug.
Hauv kev faib ua feem, kev txiav txim yog qhov tseem ceeb heev. Yog tias qhov kev txiav txim tsis raug, cov txiaj ntsig ntawm kev xam kuj yuav tsis raug thiab.
Xaus
Ob qho tib si piv thiab kev faib ua feem sib tham txog kev sib piv, tab sis sib txawv hauv cov qauv thiab kev ua haujlwm. Ib qho piv yog kev sib piv ntawm ob qho ntau thiab tsawg, thaum qhov sib piv yog ib qho lus hais tias ob qho ntau thiab tsawg sib npaug. Cov piv feem ntau yog siv los piav qhia txog kev sib xyaw lossis kev sib piv ncaj qha, thaum cov feem yog siv los daws cov teeb meem uas cuam tshuam txog kev faib ua feem thiab nrhiav cov nqi tsis paub.
Kev nkag siab txog qhov txawv ntawm ob qho no yuav pab tau ntau yam, txij li kev suav lej hauv tsev kawm ntawv thiab kev nyeem daim ntawv qhia mus txog kev xam cov zaub mov txawv thiab tsim cov phiaj xwm nqi thiab qhov ntsuas. Yog tias peb muaj cov tswv yim zoo, peb tuaj yeem siv cov piv thiab cov khoom sib piv kom raug thiab zoo.
