Unit 9
Darab Masa
Kamal berlatih piano selama 35 minit setiap hari.
Berapa minitkah dia berlatih dalam 6 hari?
时间乘法 = darab masa；每天 = setiap hari
这一课学同一段时间重复好几次，一共多久。Kamal 每天练琴 35 分钟，练 6 天，就是 35 minit × 6。乘法是把同样的时间连加几次的快捷方法。
例子：每天跳绳 8 minit，做 4 天，一共 8 × 4 = 32 minit。
注意：题目问“几分钟”，答案就用 minit 写，不必换成 jam。
multiplying time = darab masa; every day = setiap hari
In this unit the same length of time repeats several times and we find the total. Kamal practises piano for 35 minutes a day for 6 days, which is 35 minit × 6. Multiplying is a quick way to add the same time again and again.
Example: skipping rope for 8 minit a day for 4 days gives 8 × 4 = 32 minit.
Watch out: when the question asks how many minutes, write the answer in minit; there is no need to change it into jam.
Satu unit
35 minit × 6
Bentuk lazim · jawapan kekal dalam minit
| 3 | |||
| 3 | 5 | ||
| × | 6 | ||
| 2 | 1 | 0 |
35 minit × 6 = 210 minit
竖式乘法 = darab bentuk lazim
像平常的乘法一样写竖式：先乘个位，5 × 6 = 30，写 0，进 3 到十位；再乘十位，3 × 6 = 18，加进位 3 得 21。答案是 210 minit。题目用 minit，答案也用 minit。
例子：24 saat × 3 = 72 saat；13 jam × 4 = 52 jam。
注意：210 minit 已经是对的答案，不用改成别的单位。
multiplying in column form = darab bentuk lazim
Write it in column form like any multiplication: ones first, 5 × 6 = 30, so write 0 and carry 3 to the tens; then the tens, 3 × 6 = 18, plus the carried 3 makes 21. The answer is 210 minit. The question uses minutes, so the answer uses minutes too.
Example: 24 saat × 3 = 72 saat; 13 jam × 4 = 52 jam.
Watch out: 210 minit is already a correct answer; it does not need to change into another unit.
Cuba
47 saat × 3 = ?
| 4 | 7 | |
| × | 3 | |
| ? | ? |
秒乘一位数 = darab saat
个位 7 × 3 = 21，写 1，进 2；十位 4 × 3 = 12，加 2 得 14。答案 141 saat，单位还是 saat。
例子：36 saat × 2 = 72 saat。
注意：121 saat 忘了加进位的 2；1 minit 41 saat 是把 141 拆成 1 和 41，可是 1 minit 只有 60 saat，不是 100 saat。
multiplying seconds = darab saat
Ones: 7 × 3 = 21, write 1 and carry 2; tens: 4 × 3 = 12, plus 2 makes 14. The answer is 141 saat, still in seconds.
Example: 36 saat × 2 = 72 saat.
Watch out: 121 saat forgets the carried 2, and 1 minit 41 saat splits 141 into 1 and 41, but 1 minute is 60 seconds, not 100.
Kaedah kekisi
76 saat × 4
Isi petak, kemudian tambah ikut pepenjuru
76 saat × 4 = 304 saat
格子法 = kaedah kekisi
把 76 写在格子上面，4 写在右边。7 × 4 = 28，在格子里斜线上面写 2、下面写 8；6 × 4 = 24，写 2 和 4。然后从右边沿斜线相加：最右是 4；中间 8 + 2 = 10，写 0 进 1；最左 2 + 1 = 3。答案 304 saat。
例子：41 minit × 3 → 12 和 03 → 123 minit。
注意：每一格的十位写在斜线上面，个位写在斜线下面，不可以写反。
lattice method = kaedah kekisi
Write 76 above the grid and 4 on the right. 7 × 4 = 28, so write 2 above the diagonal and 8 below it; 6 × 4 = 24, so write 2 and 4. Then add along the diagonals from the right: the rightmost is 4; the middle is 8 + 2 = 10, so write 0 and carry 1; the left is 2 + 1 = 3. The answer is 304 saat.
Example: 41 minit × 3 → 12 and 03 → 123 minit.
Watch out: in each box the tens digit goes above the diagonal and the ones digit below it; do not swap them.
Tambah berulang
25 minit × 4
Garis masa: lompat 25 minit, 4 kali
25 + 25 + 25 + 25 = 25 × 4
0
25
50
75
100
4 lompatan × 25 minit = 100 minit
重复相加 = tambah berulang；时间线 = garis masa
乘法也可以看成同一个数连加：25 minit × 4 = 25 + 25 + 25 + 25。在时间线上从 0 出发，每次跳 25 minit，跳 4 次：25、50、75、100。停在 100，所以答案是 100 minit。
例子：15 saat × 3 → 15、30、45 → 45 saat。
注意：跳几次就是乘几，要数跳的次数，不是数刻度的数目。
repeated addition = tambah berulang; time line = garis masa
Multiplication can also be seen as adding the same number again and again: 25 minit × 4 = 25 + 25 + 25 + 25. On the time line, start at 0 and jump 25 minutes, 4 times: 25, 50, 75, 100. We stop at 100, so the answer is 100 minit.
Example: 15 saat × 3 → 15, 30, 45 → 45 saat.
Watch out: the number of jumps is the number we multiply by, so count the jumps, not the tick marks.
Cuba
18 jam × 5 = ?
| 1 | 8 | |
| × | 5 | |
| ? | ? |
小时乘一位数 = darab jam
个位 8 × 5 = 40，写 0，进 4；十位 1 × 5 = 5，加 4 得 9。答案 90 jam。也可以用重复相加检查：18 + 18 + 18 + 18 + 18 = 90。
例子：14 jam × 3 = 42 jam。
注意：23 jam 是把乘号当成加号；50 jam 是忘了加进位的 4。
multiplying hours = darab jam
Ones: 8 × 5 = 40, write 0 and carry 4; tens: 1 × 5 = 5, plus 4 makes 9. The answer is 90 jam. Repeated addition checks it: 18 + 18 + 18 + 18 + 18 = 90.
Example: 14 jam × 3 = 42 jam.
Watch out: 23 jam treats the times sign as a plus sign, and 50 jam forgets to add the carried 4.
Tukar tertib
62 saat × 4 = 4 × 62 saat
Tertib darab tidak mengubah jawapan
62 saat × 4
248 saat
4 × 62 saat
248 saat
62 + 62 + 62 + 62 = 248 saat
交换顺序 = tukar tertib
62 saat × 4 和 4 × 62 saat 都是“4 个 62 saat”，所以答案一样，都是 248 saat。乘法的两个数可以交换位置，答案不变。算的时候可以挑自己比较顺手的写法。
例子：3 × 21 minit = 21 minit × 3 = 63 minit。
注意：交换的是两个数的位置，单位还是跟着时间走，答案仍然写 saat。
changing the order = tukar tertib
62 saat × 4 and 4 × 62 saat both mean four lots of 62 seconds, so they give the same answer, 248 saat. The two numbers in a multiplication can swap places without changing the answer, so use whichever way feels easier.
Example: 3 × 21 minit = 21 minit × 3 = 63 minit.
Watch out: only the order of the numbers changes; the unit stays with the time, so the answer is still in saat.
Dua unit
3 jam 12 minit × 3
Darab setiap lajur
| jam | minit | |
|---|---|---|
| 3 | 12 | |
| × | 3 | |
| 9 | 36 |
分栏乘 = darab setiap lajur
有 jam 和 minit 两个单位时，竖式分成两栏，每栏各自乘同一个数。先乘 minit 栏：12 × 3 = 36 minit；再乘 jam 栏：3 × 3 = 9 jam。答案 9 jam 36 minit。这一课的题目，minit 栏乘出来都不到 60，直接照写。
例子：1 minit 15 saat × 2 = 2 minit 30 saat。
注意：两栏都要乘，只乘一栏的话另一栏还是原来的数，就错了。
multiplying each column = darab setiap lajur
With two units, jam and minit, the column form has two columns and each is multiplied by the same number. Minutes first: 12 × 3 = 36 minit; then hours: 3 × 3 = 9 jam. The answer is 9 jam 36 minit. In this unit the minute column always stays under 60, so just write it down.
Example: 1 minit 15 saat × 2 = 2 minit 30 saat.
Watch out: multiply both columns; if only one is multiplied, the other still shows the old number, which is wrong.
Cuba
2 minit 14 saat × 4 = ?
| minit | saat | |
|---|---|---|
| 2 | 14 | |
| × | 4 | |
| ? | ? |
分秒乘法 = darab minit dan saat
saat 栏：14 × 4 = 56；minit 栏：2 × 4 = 8。答案 8 minit 56 saat。
例子：3 minit 10 saat × 5 = 15 minit 50 saat。
注意：8 minit 14 saat 只乘了 minit 栏；2 minit 56 saat 只乘了 saat 栏。
multiplying minutes and seconds = darab minit dan saat
Seconds column: 14 × 4 = 56; minutes column: 2 × 4 = 8. The answer is 8 minit 56 saat.
Example: 3 minit 10 saat × 5 = 15 minit 50 saat.
Watch out: 8 minit 14 saat multiplies only the minutes, and 2 minit 56 saat multiplies only the seconds.
Situasi harian
Encik Lim memandu ke tempat kerja
1 jam 8 minit sehari · 5 hari
| jam | minit | |
|---|---|---|
| 1 | 8 | |
| × | 5 | |
| 5 | 40 |
1 jam 8 minit × 5 = 5 jam 40 minit
生活情境 = situasi harian
每天开车 1 jam 8 minit，开 5 天，同样的时间重复 5 次，所以用乘法：1 jam 8 minit × 5。minit 栏 8 × 5 = 40，jam 栏 1 × 5 = 5，一共 5 jam 40 minit。
例子：每节课 1 jam 5 minit，上 4 节 → 4 jam 20 minit。
注意：看到“每天、每次”都是同样的时间，再问“几天一共多久”，就想到乘法。
daily situation = situasi harian
Driving 1 jam 8 minit each day for 5 days repeats the same time 5 times, so multiply: 1 jam 8 minit × 5. Minutes: 8 × 5 = 40; hours: 1 × 5 = 5. Altogether 5 jam 40 minit.
Example: lessons of 1 jam 5 minit, 4 lessons → 4 jam 20 minit.
Watch out: when the same time happens each day or each time and the question asks for the total, think of multiplication.
Padankan
Hasil darab masa
配对乘积 = padankan hasil darab
23 × 3 = 69 saat；2 jam 11 minit × 4：11 × 4 = 44，2 × 4 = 8，得 8 jam 44 minit；45 × 2 = 90 minit；1 minit 7 saat × 6：7 × 6 = 42，1 × 6 = 6，得 6 minit 42 saat。
例子：32 minit × 3 = 96 minit。
注意：90 minit 和 69 saat 都保留原来的单位，配对时看单位也看数字。
matching products = padankan hasil darab
23 × 3 = 69 saat; for 2 jam 11 minit × 4, 11 × 4 = 44 and 2 × 4 = 8, giving 8 jam 44 minit; 45 × 2 = 90 minit; for 1 minit 7 saat × 6, 7 × 6 = 42 and 1 × 6 = 6, giving 6 minit 42 saat.
Example: 32 minit × 3 = 96 minit.
Watch out: 90 minit and 69 saat keep their own units, so check both the unit and the number when matching.
Ringkasan
Syabas!
satu unit × → unit sama · dua unit × → darab setiap lajur
Satu unit: darab dengan bentuk lazim, kaedah kekisi atau tambah berulang; jawapan kekal dalam unit yang sama. Dua unit: darab lajur unit kecil, kemudian lajur unit besar.
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