Unit 2
Tolak Wang
Mei Ling ada RM 50. Dia membeli sebuah buku berharga RM 23.75.
Berapakah baki wang Mei Ling?
减钱 = tolak wang；余额 = baki
这一课学把一个金额减去另一个金额。Mei Ling 有 RM 50，买了一本 RM 23.75 的书，剩下多少钱，就是用 RM 50 减去 RM 23.75，答案 RM 26.25。减钱时常常会遇到 sen 不够减，这时要向 ringgit 借。
例子：有 RM 10，买了 RM 3.20 的面包，余额是 RM 6.80。
注意：减法一定是大的金额减小的金额，余额不会比原来的钱多。
subtracting money = tolak wang; balance = baki
In this unit we take one amount away from another. Mei Ling has RM 50 and buys a book for RM 23.75; what is left is RM 50 minus RM 23.75, which is RM 26.25. When subtracting money, the sen are often too small, and then we borrow from the ringgit.
Example: with RM 10, buying bread at RM 3.20 leaves RM 6.80.
Watch out: we always subtract the smaller amount from the larger one, so the balance is never more than the money we started with.
Bentuk lazim
RM 72.40 − RM 35.65
40 sen tidak cukup, pinjam 1 ringgit
1 ringgit = 100 sen → 40 sen + 100 sen = 140 sen → 140 − 65 = 75
借位 = pinjam；不够减 = tidak cukup
减钱先对齐小数点，从 sen 减起。40 sen 不够减 65 sen，就向左边的 ringgit 借 1 ringgit：72 变成 71，而 1 ringgit 等于 100 sen，所以 40 sen 变成 140 sen。140 − 65 = 75 sen。再减 ringgit：71 − 35 = 36。答案 RM 36.75。
例子：RM 9.30 − RM 4.80 → 30 不够减 80，借 1 → 130 − 80 = 50，8 − 4 = 4 → RM 4.50。
注意：借来的 1 ringgit 是 100 sen，不是 10 sen。
borrowing = pinjam; not enough = tidak cukup
Line up the decimal points and start from the sen. 40 sen is not enough to take away 65 sen, so borrow 1 ringgit from the left: 72 becomes 71, and because 1 ringgit is 100 sen, the 40 sen become 140 sen. 140 − 65 = 75 sen. Then subtract the ringgit: 71 − 35 = 36. The answer is RM 36.75.
Example: RM 9.30 − RM 4.80 → 30 is less than 80, so borrow 1 → 130 − 80 = 50, and 8 − 4 = 4 → RM 4.50.
Watch out: the borrowed 1 ringgit is worth 100 sen, never 10 sen.
Cuba
RM 64.30 − RM 28.85 = ?
| 6 | 4 | . | 3 | 0 | |
| − | 2 | 8 | . | 8 | 5 |
| ? | ? | ? | ? | ? |
sen 不够减 = sen tidak cukup
30 sen 比 85 sen 小，所以要向 64 借 1 ringgit：64 变 63，30 sen 变 130 sen。130 − 85 = 45 sen。然后 63 − 28 = 35。答案 RM 35.45。做完可以用加法检查：35.45 + 28.85 = 64.30。
例子：RM 41.20 − RM 17.75 → 120 − 75 = 45，40 − 17 = 23 → RM 23.45。
注意：借了 1 之后，ringgit 要记得少 1，否则会多出 1 ringgit。
sen too small = sen tidak cukup
30 sen is smaller than 85 sen, so borrow 1 ringgit from 64: it becomes 63 and the 30 sen become 130 sen. 130 − 85 = 45 sen. Then 63 − 28 = 35. The answer is RM 35.45. You can check by adding: 35.45 + 28.85 = 64.30.
Example: RM 41.20 − RM 17.75 → 120 − 75 = 45, and 40 − 17 = 23 → RM 23.45.
Watch out: after borrowing, the ringgit must be 1 less, or the answer will be 1 ringgit too big.
Nombor bulat tolak sen
RM 3 000 − RM 1 246.80
Fikir RM 3 000 = RM 2 999 + 100 sen
| 3 | 0 | 0 | 0 | . | 0 | 0 | |
| − | 1 | 2 | 4 | 6 | . | 8 | 0 |
| 1 | 7 | 5 | 3 | . | 2 | 0 |
RM 3 000.00 = RM 2 999 + 100 sen · 100 − 80 = 20 sen · 2 999 − 1 246 = 1 753
整数金额 = nombor bulat；连续的 0 = sifar berturut-turut
RM 3 000 的 sen 是 00，减 80 sen 时不够。如果一位一位地借，要经过好几个 0，容易错。更简单的方法：把 RM 3 000 看成 RM 2 999 加 100 sen。先算 100 − 80 = 20 sen，再算 2 999 − 1 246 = 1 753，合起来 RM 1 753.20。
例子：RM 500 − RM 236.45 → 看成 499 和 100 sen → 100 − 45 = 55，499 − 236 = 263 → RM 263.55。
注意：整数金额减带 sen 的金额，答案一定有 sen。
whole amount = nombor bulat; zeros in a row = sifar berturut-turut
The sen part of RM 3 000 is 00, which is too small to take away 80 sen. Borrowing digit by digit across several zeros is easy to get wrong. A simpler way is to think of RM 3 000 as RM 2 999 plus 100 sen. First 100 − 80 = 20 sen, then 2 999 − 1 246 = 1 753, giving RM 1 753.20.
Example: RM 500 − RM 236.45 → think 499 and 100 sen → 100 − 45 = 55, and 499 − 236 = 263 → RM 263.55.
Watch out: a whole amount minus an amount with sen always leaves some sen in the answer.
Cuba
RM 5 000 − RM 2 375.45 = ?
| 5 | 0 | 0 | 0 | . | 0 | 0 | |
| − | 2 | 3 | 7 | 5 | . | 4 | 5 |
| ? | ? | ? | ? | ? | ? | ? |
拆成 4 999 加 100 sen = fikir 4 999 dan 100 sen
把 RM 5 000 看成 RM 4 999 和 100 sen。sen：100 − 45 = 55。ringgit：4 999 − 2 375 = 2 624。答案 RM 2 624.55。检查：2 624.55 + 2 375.45 = 5 000。
例子：RM 2 000 − RM 1 480.30 → 1 999 − 1 480 = 519，100 − 30 = 70 → RM 519.70。
注意：选项 RM 2 625.55 是忘了 5 000 已经借走 1 ringgit。
thinking of 4 999 plus 100 sen = fikir 4 999 dan 100 sen
See RM 5 000 as RM 4 999 and 100 sen. Sen: 100 − 45 = 55. Ringgit: 4 999 − 2 375 = 2 624. The answer is RM 2 624.55. Check: 2 624.55 + 2 375.45 = 5 000.
Example: RM 2 000 − RM 1 480.30 → 1 999 − 1 480 = 519 and 100 − 30 = 70 → RM 519.70.
Watch out: RM 2 625.55 forgets that 1 ringgit was already borrowed from the 5 000.
Tolak dua kali
RM 120 − RM 45.30 − RM 28.50
Tolak dari kiri ke kanan, satu demi satu
| 1 | 2 | 0 | . | 0 | 0 | |
| − | 4 | 5 | . | 3 | 0 | |
| 7 | 4 | . | 7 | 0 |
| 7 | 4 | . | 7 | 0 | |
| − | 2 | 8 | . | 5 | 0 |
| 4 | 6 | . | 2 | 0 |
Langkah 1: 120 − 45.30 = 74.70 · Langkah 2: 74.70 − 28.50 = 46.20
连减 = tolak dua kali；一步一步 = satu demi satu
算式里有两个减号，就从左边开始，先减第一个，得到的答案再减第二个。RM 120 − RM 45.30：120 看成 119 和 100 sen，100 − 30 = 70，119 − 45 = 74，得 RM 74.70。再算 RM 74.70 − RM 28.50：70 − 50 = 20，74 − 28 = 46，得 RM 46.20。
例子：RM 60 − RM 15.50 − RM 10 → 44.50 − 10 = RM 34.50。
注意：第一步算错，第二步跟着错，所以第一步要特别小心。
subtracting twice = tolak dua kali; one at a time = satu demi satu
When there are two minus signs, start from the left: subtract the first amount, then subtract the second amount from that result. RM 120 − RM 45.30: see 120 as 119 and 100 sen, 100 − 30 = 70, 119 − 45 = 74, giving RM 74.70. Then RM 74.70 − RM 28.50: 70 − 50 = 20 and 74 − 28 = 46, giving RM 46.20.
Example: RM 60 − RM 15.50 − RM 10 → 44.50 − 10 = RM 34.50.
Watch out: a slip in the first step makes the second step wrong too, so check the first result carefully.
Cuba
RM 200 − RM 68.40 − RM 51.60 = ?
| 2 | 0 | 0 | . | 0 | 0 | |
| − | 6 | 8 | . | 4 | 0 | |
| ? | ? | ? | ? | ? | ? |
| ? | |||||
| − | 5 | 1 | . | 6 | 0 |
| ? | ? | ? | ? | ? |
两步减法 = dua langkah tolak
第一步：RM 200 − RM 68.40。200 看成 199 和 100 sen，100 − 40 = 60，199 − 68 = 131，得 RM 131.60。第二步：RM 131.60 − RM 51.60，sen 刚好 60 − 60 = 0，131 − 51 = 80，得 RM 80。
例子：RM 100 − RM 30.25 − RM 19.75 → 69.75 − 19.75 = RM 50。
注意：sen 减完是 0 时，答案就是整数，写 RM 80 就可以。
two-step subtraction = dua langkah tolak
Step one: RM 200 − RM 68.40. See 200 as 199 and 100 sen, 100 − 40 = 60 and 199 − 68 = 131, giving RM 131.60. Step two: RM 131.60 − RM 51.60; the sen are 60 − 60 = 0 and 131 − 51 = 80, giving RM 80.
Example: RM 100 − RM 30.25 − RM 19.75 → 69.75 − 19.75 = RM 50.
Watch out: when the sen come to 0, the answer is a whole amount, so RM 80 is enough.
Cari nombor yang tiada
? − RM 36.80 = RM 45.20
Baki + yang ditolak = nombor asal
? − RM 36.80 = RM 45.20
Nombor asal = RM 45.20 + RM 36.80 = RM 82.00
Semak: RM 82.00 − RM 36.80 = RM 45.20 ✓
求未知的被减数 = cari nombor asal；被减数 = nombor yang ditolak daripadanya
方框在最前面，表示“原来有多少钱”。知道减掉 RM 36.80 后剩 RM 45.20，要找回原来的数，就把剩下的和减掉的加回去：45.20 + 36.80 = 82。所以方框是 RM 82。算完一定要代回去检查：82 − 36.80 = 45.20，对了。
例子：□ − RM 5.50 = RM 14.50 → 14.50 + 5.50 = RM 20。
注意：这题要用加法，不是把两个数相减。
finding the starting amount = cari nombor asal
The box at the front stands for the money we started with. We know that after taking away RM 36.80 there was RM 45.20 left, so to get the starting amount we add the balance and the amount taken away: 45.20 + 36.80 = 82. The box is RM 82. Always put it back to check: 82 − 36.80 = 45.20, which is right.
Example: □ − RM 5.50 = RM 14.50 → 14.50 + 5.50 = RM 20.
Watch out: this question needs addition, not subtracting the two numbers.
Cuba
? − RM 128.50 = RM 371.50
加回去 = tambah semula
原来的钱减掉 RM 128.50 后剩 RM 371.50，所以原来的钱是 371.50 + 128.50。sen：50 + 50 = 100，写 00 进 1。ringgit：1 + 371 + 128 = 500。方框是 RM 500。检查：500 − 128.50 = 371.50。
例子：□ − RM 40.25 = RM 59.75 → 59.75 + 40.25 = RM 100。
注意：RM 243 是把两个数相减得到的，方向反了。
adding back = tambah semula
The starting money minus RM 128.50 leaves RM 371.50, so the starting money is 371.50 + 128.50. Sen: 50 + 50 = 100, write 00 and carry 1. Ringgit: 1 + 371 + 128 = 500. The box is RM 500. Check: 500 − 128.50 = 371.50.
Example: □ − RM 40.25 = RM 59.75 → 59.75 + 40.25 = RM 100.
Watch out: RM 243 comes from subtracting the two numbers, which goes the wrong way.
Semak jawapan
RM 86.25 − RM 49.70 = RM 36.55
Jawapan + nombor yang ditolak = nombor asal
| 8 | 6 | . | 2 | 5 | |
| − | 4 | 9 | . | 7 | 0 |
| 3 | 6 | . | 5 | 5 |
| 3 | 6 | . | 5 | 5 | |
| + | 4 | 9 | . | 7 | 0 |
| 8 | 6 | . | 2 | 5 |
Tolak: 86.25 − 49.70 = 36.55 · Semak: 36.55 + 49.70 = 86.25 ✓
验算 = semak；加法 = tambah
减法做完，用加法来检查最保险。RM 86.25 − RM 49.70：25 不够减 70，借 1，125 − 70 = 55，85 − 49 = 36，答案 RM 36.55。检查：把答案加上减掉的数，36.55 + 49.70，sen 55 + 70 = 125 写 25 进 1，1 + 36 + 49 = 86，得 RM 86.25，跟原来的数一样，所以没错。
例子：RM 20 − RM 7.35 = RM 12.65，检查 12.65 + 7.35 = RM 20。
注意：如果加回去不等于原来的数，就要重新减一次。
checking = semak; addition = tambah
After subtracting, the safest check is to add. RM 86.25 − RM 49.70: 25 is less than 70, so borrow 1, 125 − 70 = 55 and 85 − 49 = 36, giving RM 36.55. To check, add the answer to the amount taken away: 36.55 + 49.70, sen 55 + 70 = 125, write 25 and carry 1, then 1 + 36 + 49 = 86, giving RM 86.25, the same as the starting amount, so the answer is correct.
Example: RM 20 − RM 7.35 = RM 12.65; check 12.65 + 7.35 = RM 20.
Watch out: if adding back does not give the starting amount, do the subtraction again.
Padankan
Baki yang betul
配对余额 = padankan baki
每条算式先看 sen 够不够减。50 − 12.30：看成 49 和 100 sen，100 − 30 = 70，49 − 12 = 37，得 RM 37.70。100 − 62.55：99 和 100 sen，100 − 55 = 45，99 − 62 = 37，得 RM 37.45。9.80 − 4.90：80 不够减 90，借 1，180 − 90 = 90，8 − 4 = 4，得 RM 4.90。600 − 275 = RM 325。
例子：RM 30 − RM 11.20 → 29 和 100 sen → RM 18.80。
注意：RM 37.70 和 RM 37.45 很像，要看清 sen 的数字。
matching balances = padankan baki
For each sum, first see whether the sen are enough. 50 − 12.30: think 49 and 100 sen, 100 − 30 = 70 and 49 − 12 = 37, giving RM 37.70. 100 − 62.55: 99 and 100 sen, 100 − 55 = 45 and 99 − 62 = 37, giving RM 37.45. 9.80 − 4.90: 80 is less than 90, so borrow 1, 180 − 90 = 90 and 8 − 4 = 4, giving RM 4.90. 600 − 275 = RM 325.
Example: RM 30 − RM 11.20 → 29 and 100 sen → RM 18.80.
Watch out: RM 37.70 and RM 37.45 look alike, so read the sen digits carefully.
Ringkasan
Syabas!
sen dahulu → pinjam 1 ringgit = 100 sen → semak dengan tambah
Susun titik perpuluhan sebaris. Jika sen tidak cukup, pinjam 1 ringgit dan jadikan 100 sen. Tolak dua kali dibuat dari kiri ke kanan. Semak jawapan dengan tambah.
Latihan tambahan →