← Bab 2
Unit 5 · Tolak Pecahan
Unit 5

Tolak Pecahan

Ada 156 biji tembikai di atas meja. Adik makan 16 biji.
Berapakah tembikai yang tinggal?

Tolak Pecahan
分数减法 = tolak pecahan 从原有的数量里拿走一部分,求剩下多少,要用减法。这个单元学分数、带分数和整数的减法,包括分母不同、需要借 1、连减两个数的情况,答案要写成最简形式。 例子:4/5 − 1/5 = 3/5。 注意:减以前先看分母是否相同。
subtracting fractions = tolak pecahan Taking part of an amount away and finding what is left needs subtraction. In this unit we subtract fractions, mixed numbers and whole numbers, including different denominators, borrowing 1 and taking away two numbers in a row, and give answers in simplest form. Example: 4/5 − 1/5 = 3/5. Watch out: before subtracting, check whether the denominators are the same.
Penyebut sama

Tolak pengangka sahaja

156 − 16

156 − 16 = 15 − 16 = 146 = 123
同分母相减 = penyebut sama 分母相同,每份一样大,只要把分子相减:五份减一份剩四份,分母仍是六,得 1又4/6。四和六都能被二整除,约简成 1又2/3,这就是最简形式。 例子:2又7/8 − 3/8 = 2又4/8 = 2又1/2。 注意:分母保持不变,答案要约简。
same denominators = penyebut sama With the same denominator the parts are the same size, so subtract the numerators: 5 parts − 1 part = 4 parts, with the denominator 6, giving 1 4/6. Both 4 and 6 divide by 2, so it simplifies to 1 2/3. Example: 2 7/8 − 3/8 = 2 4/8 = 2 1/2. Watch out: keep the denominator and simplify the answer.
Cari kesilapan

59 − 29 = 30?

✘ Salah

59 − 29 = 30
penyebut ditolak

✔ Betul

59 − 29 = 39 = 13
找错 = cari kesilapan 把分母也相减,九减九得零,变成分母是零的分数,这是没有意义的,因为分母表示把整体分成几份,不能是零。正确做法是分母保持九,只减分子,得九分之三,再约成三分之一。 例子:6/7 − 2/7 = 4/7。 注意:加法和减法都不能改变分母。
find the mistake = cari kesilapan Subtracting the denominators as well gives 9 − 9 = 0, and a denominator of 0 has no meaning, because the denominator tells how many parts the whole is cut into. The correct way keeps 9 and subtracts only the numerators: 3/9, which simplifies to 1/3. Example: 6/7 − 2/7 = 4/7. Watch out: adding and subtracting never change the denominator.
Tolak daripada 1

1 = pecahan yang sama penyebut

1 − 38

1 − 3/8 = 8/8 − 3/8 = 5/8
从 1 减 = tolak daripada 1 1 可以写成分母相同的分数:要减八分之几,就把 1 写成八分之八。八份减三份剩五份,所以答案是八分之五。在数线上从 1 往左数三格,也停在八分之五。 例子:1 − 2/5 = 5/5 − 2/5 = 3/5。 注意:1 要换成和另一个分数一样的分母。
subtract from 1 = tolak daripada 1 1 can be written as a fraction with the same denominator: to take away eighths, write 1 as 8/8. 8 parts − 3 parts = 5 parts, so 5/8. On the number line, count 3 steps back from 1 and you also land on 5/8. Example: 1 − 2/5 = 5/5 − 2/5 = 3/5. Watch out: write 1 with the same denominator as the other fraction.
Nombor bulat − nombor bercampur

Dua cara

5 − 223

Cara 1: pinjam 1

433 − 223
= 213

Cara 2: tak wajar

153 − 83
= 73 = 213
整数减带分数 = nombor bulat tolak nombor bercampur 方法一:从 5 借出 1,写成 4又3/3,这样分数部分就够减:4又3/3 − 2又2/3 = 2又1/3。方法二:把两个数都换成假分数:5 = 15/3,2又2/3 = 8/3,15/3 − 8/3 = 7/3 = 2又1/3。 例子:4 − 1又1/4 = 3又4/4 − 1又1/4 = 2又3/4。 注意:借出的 1 要换成分母相同的分数。
whole number minus a mixed number = nombor bulat tolak nombor bercampur Method 1: borrow 1 from 5 and write 4 3/3, so the fraction part can be subtracted: 4 3/3 − 2 2/3 = 2 1/3. Method 2: change both into improper fractions: 5 = 15/3 and 2 2/3 = 8/3, and 15/3 − 8/3 = 7/3 = 2 1/3. Example: 4 − 1 1/4 = 3 4/4 − 1 1/4 = 2 3/4. Watch out: the borrowed 1 must be written with the same denominator.
Tolak berturut-turut

Tukar kepada pecahan tak wajar

715 − 35 − 345

Cara 1: pinjam 1

665 − 35 = 635
585 − 345 = 245

Cara 2: tak wajar

365 − 35 − 195
= 145 = 245
连减 = tolak berturut-turut 方法一(借 1):7又1/5 的分数部分不够减 3/5,借 1 写成 6又6/5,减后得 6又3/5;再减 3又4/5 时又不够减,再借 1 写成 5又8/5,减后得 2又4/5。方法二(假分数):7又1/5 = 36/5,3又4/5 = 19/5,分子连减 36 − 3 − 19 = 14,得 14/5 = 2又4/5。两种方法答案相同。 例子:3又1/4 − 1/4 − 1又3/4 = 13/4 − 1/4 − 7/4 = 5/4 = 1又1/4。 注意:从左到右连续减,不要漏掉任何一个数。
subtract twice = tolak berturut-turut Method 1 (borrow 1): 1/5 is less than 3/5, so write 7 1/5 as 6 6/5 and subtract to get 6 3/5; 3/5 is less than 4/5, so borrow again, 5 8/5 − 3 4/5 = 2 4/5. Method 2 (improper fractions): 7 1/5 = 36/5 and 3 4/5 = 19/5, and 36 − 3 − 19 = 14, giving 14/5 = 2 4/5. Both methods agree. Example: 3 1/4 − 1/4 − 1 3/4 = 13/4 − 1/4 − 7/4 = 5/4 = 1 1/4. Watch out: subtract from left to right and do not miss any number.
Penyebut berbeza

Cari penyebut sama (GSTK) dengan sifir

434 − 216

Sifir 4 dan 6

46
46
812
1218

Kira

2 + 912 − 212
= 2712
异分母带分数相减 = penyebut berbeza 先减整数:4 − 2 = 2。分数部分分母不同,用倍数表找最小公分母(也就是两个分母的最小公倍数,马来文叫 GSTK,gandaan sepunya terkecil):四的倍数四、八、十二,六的倍数六、十二,所以是十二。四分之三换成十二分之九,六分之一换成十二分之二,相减得十二分之七。答案 2又7/12。 例子:3又1/2 − 1又1/3 = 2 + 3/6 − 2/6 = 2又1/6。 注意:换分母时,分子也要乘同一个数。
different denominators = penyebut berbeza Subtract the whole numbers first: 4 − 2 = 2. The fractions have different denominators, so use the times tables to find the smallest common denominator, 12. This is the lowest common multiple, called GSTK (gandaan sepunya terkecil) in Malay. 3/4 = 9/12 and 1/6 = 2/12, and 9/12 − 2/12 = 7/12. The answer is 2 7/12. Example: 3 1/2 − 1 1/3 = 2 + 3/6 − 2/6 = 2 1/6. Watch out: when changing the denominator, multiply the numerator by the same number.
Anu

237 − □ = 157

Nombor yang ditolak = nombor asal − jawapan

177 − □ = 127
□ = 177 − 127 = 57
减法中的未知数 = anu dalam tolak 要求被减去的数,用原来的数减去剩下的数。先把两个带分数都换成七分之几:2又3/7 是十七份,1又5/7 是十二份。十七份减十二份等于五份,所以缺的是七分之五。放回去检查:2又3/7 − 5/7 = 1又5/7,对了。 例子:2 − □ = 1又1/4 → □ = 3/4。 注意:先统一成假分数,比较不容易算错。
the unknown in subtraction = anu dalam tolak To find the number taken away, subtract what is left from the starting number. Change both mixed numbers into sevenths: 2 3/7 is 17 sevenths and 1 5/7 is 12 sevenths. 17 − 12 = 5, so the missing number is 5/7. Check: 2 3/7 − 5/7 = 1 5/7. Example: 2 − □ = 1 1/4, so □ = 3/4. Watch out: using improper fractions makes mistakes less likely.
Tiga penyebut berbeza

Dua langkah

513 − 14 − 156

Cara 1: pinjam 1

5412 − 312 = 5112
41312 − 11012
= 3312 = 314

Cara 2: tak wajar

6412 − 312 − 2212
= 3912 = 3312
= 314
三个不同分母 = tiga penyebut berbeza 三、四、六的最小公分母是十二,把三个分数都换成十二分之几。第一步从左减:5又4/12 − 3/12 = 5又1/12。第二步分数部分十二分之一不够减十二分之十,要借一:写成 4又13/12,再减得 3又3/12,约简成 3又1/4。方法二是全部换成假分数:64/12 − 3/12 − 22/12 = 39/12 = 3又1/4,答案一样。 例子:2又1/2 − 1/4 − 1/8 = 2又4/8 − 2/8 − 1/8 = 2又1/8。 注意:分数不够减时,从整数借 1。
three different denominators = tiga penyebut berbeza The smallest common denominator of 3, 4 and 6 is 12, so change all three into twelfths. Step 1, from the left: 5 4/12 − 3/12 = 5 1/12. Step 2: 1/12 is less than 10/12, so borrow 1 and write 4 13/12, then subtract to get 3 3/12, which simplifies to 3 1/4. Method 2 uses improper fractions: 64/12 − 3/12 − 22/12 = 39/12 = 3 1/4, the same answer. Example: 2 1/2 − 1/4 − 1/8 = 2 4/8 − 2/8 − 1/8 = 2 1/8. Watch out: when the fraction is too small, borrow 1 from the whole number.
Nombor bulat tolak dua pecahan

Tolak satu demi satu

8 − 325 − 34

8 − 325 = 435
41220 − 1520 = 33220 − 1520 = 31720
整数连减两个分数 = nombor bulat tolak dua pecahan 第一步:8 − 3又2/5,从 8 借 1 写成 7又5/5,减后得 4又3/5。第二步:五和四的最小公分母是二十,4又3/5 换成 4又12/20,四分之三换成二十分之十五。十二不够减十五,再借一,变成 3又32/20,减后得 3又17/20。 例子:5 − 1又1/2 − 1/3 = 3又1/2 − 1/3 = 3又1/6。 注意:每一步都检查分数够不够减。
a whole number minus two fractions = nombor bulat tolak dua pecahan Step 1: 8 − 3 2/5; borrow 1 from 8 to write 7 5/5, leaving 4 3/5. Step 2: the smallest common denominator of 5 and 4 is 20, so 4 3/5 = 4 12/20 and 3/4 = 15/20. 12 is less than 15, so borrow again to get 3 32/20, and subtract to get 3 17/20. Example: 5 − 1 1/2 − 1/3 = 3 1/2 − 1/3 = 3 1/6. Watch out: at each step check whether the fraction is big enough to subtract from.
Semak cepat

710 − 310 = ?

同分母相减再约简 = tolak dan permudahkan 分母相同时,只把分子相减,分母保持不变;减完以后,找一个能同时整除分子和分母的数,把分数约到最简形式。题目要求最简形式。 例子:9/12 − 3/12 = 6/12 = 1/2。 注意:分母不能相减,分母变成零的分数是没有意义的。
subtract and simplify = tolak dan permudahkan When the denominators are the same, subtract only the numerators and keep the denominator. Then find a number that divides both the numerator and the denominator and simplify. The question asks for simplest form. Example: 9/12 − 3/12 = 6/12 = 1/2. Watch out: never subtract the denominators; a fraction with a denominator of zero has no meaning.
Pinjam 1

3 − 158 = ?

借 1 = pinjam 1 整数没有分数部分,不能直接减带分数。从整数借出 1,写成“几又八分之八”,然后整数减整数、分数减分数。最后用加法检查:答案加上被减的数,要等于原来的整数。 例子:2 − 1/6 = 1又6/6 − 1/6 = 1又5/6。 注意:借了 1 以后,整数部分要少 1;整数部分也要记得相减。
borrow 1 = pinjam 1 A whole number has no fraction part, so borrow 1 and write it as eighths over eighths. Then subtract whole from whole and fraction from fraction. Check by adding the answer to the number taken away; you should get the whole number back. Example: 2 − 1/6 = 1 6/6 − 1/6 = 1 5/6. Watch out: after borrowing, the whole number is 1 smaller, and remember to subtract the whole numbers too.
Penyebut berbeza

312 − 123 = ?

异分母并借位 = penyebut berbeza dan pinjam 先找两个分母的最小公分母,把两个分数部分都换成同一个分母。然后比较:前面的分数部分如果比后面的小,就要从整数借 1,再减。 例子:2又1/4 − 1又1/2 = 2又1/4 − 1又2/4 = 1又5/4 − 1又2/4 = 3/4。 注意:不够减时,不可以把两个分数部分倒过来减,要借 1。
different denominators with borrowing = penyebut berbeza dan pinjam Find the smallest common denominator and change both fraction parts to it. Then compare them: if the first fraction part is smaller, borrow 1 from the whole number before subtracting. Example: 2 1/4 − 1 1/2 = 2 1/4 − 1 2/4 = 1 5/4 − 1 2/4 = 3/4. Watch out: when the first fraction is too small, do not swap the fractions round; borrow 1 instead.
Ringkasan

Syabas!

−

Samakan penyebut, pinjam 1 jika perlu, dan permudahkan jawapan.

Latihan tambahan →