← Bab 2
Unit 19 · Selesaikan Masalah
Unit 19

Selesaikan Masalah

Masalah pecahan, perpuluhan dan peratus juga diselesaikan dengan empat langkah:
① Fahami soalan ② Fikir cara ③ Selesaikan ④ Semak

Selesaikan Masalah
解决问题 = selesaikan masalah 分数、小数和百分比的应用题,也用四个步骤来做:先理解题目,找出已知资料和要求的东西;再想用加、减、乘、除中的哪一种;然后计算;最后用相反的运算或估计来检查。答案要写上单位,例如公斤、米或百分比。 例子:有 2.5 米绳子,剪掉 1.2 米 → 用减法 → 1.3 米 → 1.3 + 1.2 = 2.5。 注意:每一题最后都要写答句。
problem solving = selesaikan masalah Word problems with fractions, decimals and percentages use the same four steps: understand the question, choose add, subtract, multiply or divide, solve, then check with the opposite operation or an estimate. Always give the unit, such as kg, m or %. Example: 2.5 m of rope with 1.2 m cut off: subtract to get 1.3 m; check 1.3 + 1.2 = 2.5. Watch out: finish every problem with an answer sentence.
Tambah pecahan

Jumlah jisim tiga bungkus

Mira membeli 134 kg gula, 2 kg garam dan 318 kg tepung. Berapakah jumlah jisim semuanya?
Fahami soalan
• 3 jisim
• cari jumlah
Fikir cara
Tambah. Tukar 34 kepada 68.
Selesaikan
168 + 2 + 318
= 678 kg
Semak
678 − 318 − 2 = 134 ✔
带分数连加 = tambah nombor bercampur 题目问一共多重,要把三包的重量加起来。分母四和八不同,先把四分之三化成八分之六。整数部分一加二加三得六,分数部分八分之六加八分之一得八分之七,所以一共六又八分之七公斤。用减法倒回去检查。 例子:1又1/2 + 2 + 1又1/4 = 4又3/4。 注意:整数 2 也要加进去。
adding mixed numbers = tambah nombor bercampur The question asks for the total mass, so add all three. The denominators 4 and 8 differ, so change 3/4 to 6/8. Wholes: 1 + 2 + 3 = 6; fractions: 6/8 + 1/8 = 7/8. The total is 6 7/8 kg. Check by subtracting back. Example: 1 1/2 + 2 + 1 1/4 = 4 3/4. Watch out: include the whole number 2.
Pecahan daripada kuantiti

Beza dua kumpulan

Ada 180 orang murid. 49 daripadanya naik bas dan 13 berjalan kaki. Berapa orang lebih ramai naik bas daripada berjalan kaki?
Fahami soalan
• 180 murid
• cari beza
Fikir cara
Cari setiap kumpulan, kemudian tolak.
Selesaikan
49 × 180 = 80
13 × 180 = 60
80 − 60 = 20
Semak
60 + 20 = 80 ✔
分数的量再求差 = pecahan daripada kuantiti dan beza 先分别求两组人数:一百八十除以九得二十,再乘四得八十人坐巴士;一百八十除以三得六十人走路。题目问多多少人,所以用减法,八十减六十得二十人。 例子:60 的 1/2 是 30,60 的 1/3 是 20,相差 10。 注意:要先分别求出两组人数再相减,或先求两个分数的差(4/9 − 1/3 = 1/9)再乘总数;不要只算一组就停。
a fraction of a quantity, then the difference = pecahan daripada kuantiti dan beza Find each group: 180 ÷ 9 × 4 = 80 take the bus, and 180 ÷ 3 = 60 walk. The question asks how many more, so subtract: 80 − 60 = 20 pupils. Example: 1/2 of 60 is 30 and 1/3 of 60 is 20, a difference of 10. Watch out: find both groups and then subtract, or find the difference of the fractions first (4/9 − 1/3 = 1/9) and multiply by the total; do not stop after one group.
Lebih daripada

Jumlah panjang dua reben

Reben merah 1.35 m. Reben biru 0.75 m lebih panjang daripada reben merah. Berapakah jumlah panjang kedua-dua reben?
Fahami soalan
• biru = merah + 0.75
• cari jumlah
Fikir cara
Cari panjang biru, kemudian tambah.
Selesaikan
1.35 + 0.75 = 2.10
1.35 + 2.10 = 3.45 m
Semak
3.45 − 2.10 = 1.35 ✔
“比……多”再求总和 = lebih daripada 蓝丝带比红丝带长零点七五米,所以蓝丝带是一点三五加零点七五,得二点一米。题目问两条一共多长,还要再把红丝带和蓝丝带加起来,一点三五加二点一零得三点四五米。 例子:A 是 2 m,B 比 A 长 0.5 m → B = 2.5 m,共 4.5 m。 注意:2.10 m 只是蓝丝带,不是答案。
more than, then the total = lebih daripada The blue ribbon is 0.75 m longer than the red, so blue = 1.35 + 0.75 = 2.10 m. The question asks for both together, so add again: 1.35 + 2.10 = 3.45 m. Example: A is 2 m and B is 0.5 m longer, so B = 2.5 m and the total is 4.5 m. Watch out: 2.10 m is only the blue ribbon, not the answer.
Bahagi perpuluhan

Beras dalam setiap bekas

23.52 kg beras dibahagi sama banyak ke dalam 6 buah bekas. Berapakah jisim beras dalam setiap bekas?
Fahami soalan
• 23.52 kg
• 6 bekas sama banyak
Fikir cara
Bahagi sama banyak → bahagi.
Selesaikan
23.52 ÷ 6
= 3.92 kg
Semak
3.92 × 6 = 23.52 ✔
小数除法 = bahagi perpuluhan 平均分到六个容器,所以用除法。二十三除以六得三余五;五个一和五个十分之一合成五十五个十分之一,除以六得九余一;余下的一个十分之一和两个百分之一合成十二个百分之一,除以六得二。答案三点九二公斤。 例子:9.6 ÷ 4 = 2.4。 注意:商的小数点要和被除数的小数点对齐。
dividing decimals = bahagi perpuluhan Shared equally into 6 containers means divide. 23 ÷ 6 = 3 remainder 5; 55 tenths ÷ 6 = 9 remainder 1; 12 hundredths ÷ 6 = 2. The answer is 3.92 kg. Check: 3.92 × 6 = 23.52. Example: 9.6 ÷ 4 = 2.4. Watch out: line up the decimal point in the answer with the one in the number being divided.
Peratus

Peratus setem Malaysia

Farid ada 50 keping setem. 18 keping ialah setem Malaysia. Berapa peratus setem Malaysia?
Fahami soalan
• 18 daripada 50
Fikir cara
Tulis pecahan, jadikan perseratus atau darab dengan 100%.
Selesaikan
1850 = 36100 = 36%
atau 1850 × 100% = 36%
Semak
36% × 50 = 36100 × 50 = 18 ✔
百分比应用题 = masalah peratus 先写分数:马来西亚邮票十八张,全部五十张,所以是五十分之十八。五十乘二等于一百,分子也乘二,得一百分之三十六,就是百分之三十六。也可以直接乘以 100%:18/50 × 100% = 36%。检查:用“百分比 × 全部”倒回去,36% × 50 = 36/100 × 50 = 18,正好是马来西亚邮票的张数。 例子:50 个里面 10 个 → 20%。 注意:分母要用全部的数量五十。
a percentage problem = masalah peratus Write the fraction first: 18 Malaysian stamps out of 50 is 18/50. 50 × 2 = 100, so 18/50 = 36/100 = 36%. Or multiply by 100%: 18/50 × 100% = 36%. Check with percentage × total: 36% × 50 = 36/100 × 50 = 18, the number of Malaysian stamps. Example: 10 out of 50 is 20%. Watch out: the denominator is the whole group, 50.
Cuba

Tong ada 13.4 ℓ minyak. 4.75 ℓ digunakan pada hari Isnin dan 3.8 ℓ pada hari Selasa. Berapakah minyak yang tinggal?

连减 = tolak berturut-turut 按四个步骤:理解——原来有多少油,用掉了几次;想方法——每次用掉都要减,所以连减两次(或先把两次用掉的加起来再减);计算时补 0、对齐小数点;最后把剩下的和用掉的全部加起来,看是否回到原来的油量。 例子:10 − 2.5 − 3.25 = 7.5 − 3.25 = 4.25;检查 4.25 + 3.25 + 2.5 = 10。 注意:两天都用了油,只减一天的就停下来是不够的。
subtract twice = tolak berturut-turut Use the four steps: understand how much oil there was and how many times some was used; plan to subtract each amount used (or add the amounts used and subtract once); fill in zeros and line up the points; then check that what is left plus what was used makes the starting amount. Example: 10 − 2.5 − 3.25 = 7.5 − 3.25 = 4.25; check 4.25 + 3.25 + 2.5 = 10. Watch out: oil was used on two days, so subtracting only one day is not enough.
Cuba

Harga 4 buah buku yang sama ialah RM27.40. Berapakah harga sebuah buku?

求一份 = cari harga sebuah 几样东西价钱一样,已知总价,求一样的价钱,就用除法:总价 ÷ 数量。用长除法,商的小数点对齐;不够除的时候把余数和下一位合起来继续除。最后用“一样的价钱 × 数量”检查是否等于总价。 例子:RM12.60 ÷ 3 = RM4.20;检查 4.20 × 3 = 12.60。 注意:求一份要用除法;每一步的余数都要带到下一位,商的小数点要对齐。
find the price of one = cari harga sebuah When several items cost the same and the total is known, divide to find one: total ÷ number of items. Use long division with the point lined up, carrying each remainder into the next place. Check by multiplying the price of one by the number of items. Example: RM12.60 ÷ 3 = RM4.20; check 4.20 × 3 = 12.60. Watch out: finding one share needs division; carry every remainder along and line up the point in the quotient.
Ringkasan

Syabas!

4 langkah

Fahami soalan, fikir cara, selesaikan dan semak. Tulis unit dalam jawapan.

Latihan tambahan →