Cov lus txhais sai thiab yooj yim tshaj plaws rau feem seem yog qhov nws sawv cev ntawm ib feem ntawm tus lej (tag nrho). Vim li no, txawm hais tias nws tsis nyiam ntau yam xim, nws tuaj yeem siv nrog ntau qhov tseem ceeb hauv neeg lub neej txhua hnub.

Nws yog cov lej sawv cev ntawm cov ntau, ua tau kom tiav cov haujlwm xws li ntxiv, rho tawm, sib faib thiab faib.

Qhov zauv seem tuaj yeem sawv cev nyob rau ntau qhov: ntawm tus lej kab (1/2), uas txhais tau tias ib nrab ntawm ib tus lej tau raug tshem tawm. Ntawd yog, tus lej sawv cev los ntawm 1/2 yog nruab nrab ntawm xoom (0) thiab ib (1). Nws kuj yuav siv daim ntawv ntawm feem pua, tooj decimals (tooj nrog ib tus tsis nco qab) thiab cov lej sib xyaw.

Kev ua haujlwm sawv cev ib hnub dhau ib hnub

Txhawm rau pom pes tsawg feem cuam tshuam hauv tib neeg lub neej, xyuam xim rau qee qhov ua piv txwv:

Pizza nrog phooj ywg

Ib qho yooj yim ncig mus rau pizzeria nrog cov phooj ywg tuaj yeem sawv cev ntawm cov chav kawm lej tiag, qhov twg lub ntsiab lus yog feem. Tsis ntseeg? Yog li ntawd them mloog! Koj ua tau zoo pizza los ntawm tus tos.

Thaum nws mus txog lub rooj nws muab faib ua yim daim. Ntawd yog, txhua feem ntawm hu ua 1/8 (ib yim). Yog tias koj noj peb lub ncuav pizza, nws txhais tau tias koj tau noj 3/8 (peb-yim).

Daim Ntawv Qhia Ua Chav Ua Noj

Lwm txoj hauv kev los nrhiav kev siv kev faib ua feem yog los ntawm kev ua noj zaub mov txawv. Piv txwv li, yog tias 1/2 khob suab thaj tshwm hauv cov ntawv teev khoom noj, txhais tau tias koj yuav tsum ntxiv ib nrab khob.

Raws li rau feem pua, nws tseem yog ib hom ntawv ntawm qhov feem. Yog tias tib daim ntawv qhia koj thov ntxiv 3/4 ntawm ib diav hmoov txhuv, uas li 75% ntawm tag nrho.

Suav nyiaj

Txheej txheem kab ke yog lwm txoj hauv kev siv ntu feem xyuam. Yog tias koj txiav txim siab qhov nyiaj ntawm R $ 10, piv txwv li, raws li sawv cev ntawm tag nrho, R $ 1 yuav yog ib feem kaum ntawm tus nqi. Hauv lwm lo lus, (R $ 1) sib raug mus rau feem ntawm ib feem (R $ 10).