Unit 9
Darab dan Bahagi Wang
Kedai Roti Harum membeli 7 buah ketuhar. Harga sebuah ketuhar RM1 380.
Kos itu ditanggung sama banyak oleh 3 cawangan. Berapakah kos bagi setiap cawangan?

乘除混合 = darab dan bahagi
先要知道七台烤炉一共多少钱,用乘法;再把总数平均分给三间分店,用除法。所以算式里有乘也有除,要从左到右一步一步算。这个单元也学先除后乘,以及用约简让计算更容易。
例子:4 × RM300 ÷ 2 = RM1 200 ÷ 2 = RM600。
注意:按算式的次序,从左到右。
multiplying and dividing = darab dan bahagi
First find the total cost of 7 ovens by multiplying, then share it equally among 3 branches by dividing. The number sentence has × and ÷, worked from left to right. We also learn to divide first and to simplify to make the work easier.
Example: 4 × RM300 ÷ 2 = RM1 200 ÷ 2 = RM600.
Watch out: follow the order of the sentence, from left to right.
Darab dahulu
Kemudian bahagi
7 × RM1 380 ÷ 3
先乘后除 = darab dahulu
第一步:七乘一千三百八十,得九千六百六十令吉,这是七台烤炉的总价。第二步:九千六百六十除以三,得三千二百二十令吉,这是每间分店要分担的钱。
例子:6 × RM500 ÷ 3 = RM3 000 ÷ 3 = RM1 000。
注意:第一步的积就是第二步的被除数。
multiply first = darab dahulu
Step 1: 7 × RM1 380 = RM9 660, the total for 7 ovens. Step 2: RM9 660 ÷ 3 = RM3 220, the share for each branch.
Example: 6 × RM500 ÷ 3 = RM3 000 ÷ 3 = RM1 000.
Watch out: the answer to step 1 is the number divided in step 2.
Bahagi dahulu
Yuran 45 peserta → yuran 12 peserta
RM38 250 ÷ 45 × 12
RM38 250 ÷ 45 = RM850 seorang
RM850 × 12 = RM10 200
RM850 × 12 = RM10 200
先除后乘 = bahagi dahulu
四十五位营员的营费一共三万八千二百五十令吉,要求诗蒂学校十二位营员的营费,先求一个人:三万八千二百五十除以四十五,得八百五十令吉。再乘十二,得一万零二百令吉。
例子:10 本书 RM120,3 本 = RM120 ÷ 10 × 3 = RM36。
注意:先求“一个”的价钱,再求“几个”。
divide first = bahagi dahulu
The camp fee for 45 participants is RM38 250. To find the fee for Siti's school's 12 participants, first find one: RM38 250 ÷ 45 = RM850. Then × 12 = RM10 200.
Example: 10 books cost RM120, so 3 books cost RM120 ÷ 10 × 3 = RM36.
Watch out: find the amount for one first, then for several.
Permudahkan
24 ÷ 8 = 3
24 × RM1 836.45 ÷ 8
24 × RM1 836.45 ÷ 8
= (24 ÷ 8) × RM1 836.45
= 3 × RM1 836.45 = RM5 509.35
= (24 ÷ 8) × RM1 836.45
= 3 × RM1 836.45 = RM5 509.35
约简 = permudahkan
先乘二十四再除以八,数字会很大。可以先把二十四和八约简:二十四除以八等于三,所以整道题变成三乘一千八百三十六令吉四十五仙,得五千五百零九令吉三十五仙,简单多了。
例子:12 × RM250 ÷ 4 = 3 × RM250 = RM750。
注意:只有乘数和除数可以这样约简。
simplify = permudahkan
Multiplying by 24 first gives a big number. Instead simplify 24 and 8: 24 ÷ 8 = 3, so the question becomes 3 × RM1 836.45 = RM5 509.35, which is much easier.
Example: 12 × RM250 ÷ 4 = 3 × RM250 = RM750.
Watch out: only the number multiplied by and the number divided by can be simplified like this.
Cari kesilapan
RM36 000 ÷ 4 × 6
Siapakah yang betul?
✔ Ana
RM36 000 ÷ 4 = RM9 000
RM9 000 × 6 = RM54 000
RM9 000 × 6 = RM54 000
✘ Bala
4 × 6 = 24
RM36 000 ÷ 24 = RM1 500
RM36 000 ÷ 24 = RM1 500
找错 = cari kesilapan
算式是三万六千除以四再乘六,要从左到右算:先除以四得九千,再乘六得五万四千令吉。巴拉先把四和六相乘,变成除以二十四,改变了算式的意思,所以答案一千五百是错的。安娜是对的。
例子:RM100 ÷ 2 × 5 = RM50 × 5 = RM250,不是 RM100 ÷ 10 = RM10。
注意:乘除混合要从左到右。
find the mistake = cari kesilapan
The sentence is RM36 000 ÷ 4 × 6, worked from left to right: ÷ 4 = RM9 000, then × 6 = RM54 000. Bala multiplied 4 × 6 first and divided by 24, which changes the meaning, so RM1 500 is wrong. Ana is right.
Example: RM100 ÷ 2 × 5 = RM50 × 5 = RM250, not RM100 ÷ 10 = RM10.
Watch out: with × and ÷, work from left to right.
Semak cepat
8 × RM5 000 ÷ 5 = ?
先乘后除 = darab dahulu
算式先乘后除,按从左到右:先求积,再除。也可以先约简:金额是五的倍数,可以先把金额除以五,再乘前面的数,这样数字比较小。两种方法结果一定一样。
例子:3 × RM400 ÷ 2 = RM1 200 ÷ 2 = RM600,或 3 × (RM400 ÷ 2) = 3 × RM200 = RM600。
注意:乘完一定还要除;只乘不除,金额会大好几倍。
multiply first = darab dahulu
The sentence multiplies and then divides, so from left to right: find the product, then divide. Or simplify first: the amount is a multiple of 5, so divide it by 5 and then multiply, which keeps the numbers small. Both ways must agree.
Example: 3 × RM400 ÷ 2 = RM1 200 ÷ 2 = RM600, or 3 × (RM400 ÷ 2) = 3 × RM200 = RM600.
Watch out: after multiplying you still have to divide; skipping it makes the amount several times too big.
Semak cepat
RM9 000 ÷ 6 × 5 = ?
从左到右 = dari kiri ke kanan
这题先除后乘。第一步把金额除以六,得到一份;第二步把一份乘五,得到五份。不能先把六和五相乘再去除,那会改变算式的意思。
例子:RM800 ÷ 4 × 3,先得 RM200,再得 RM600。
注意:第一步得到的只是一份,还没有乘五。
left to right = dari kiri ke kanan
This sentence divides and then multiplies. Step 1 divides the amount by 6 to get one part; step 2 multiplies that part by 5. Do not multiply 6 × 5 first and then divide; that changes the meaning.
Example: RM800 ÷ 4 × 3; first RM200, then RM600.
Watch out: step 1 gives only one part; it still has to be multiplied by 5.
Ringkasan