Unit 9
Selesaikan Masalah
Kedai Encik Ravi menjual pelbagai barang.
Dia mahu menyusun barang yang berbentuk prisma di satu rak.
Barang manakah yang patut diletakkan di rak itu?
解决问题 = selesaikan masalah
Ravi 先生的店卖很多东西，他想把形状是棱柱的东西排在同一个架子上。哪些东西该放上去？这一课学用解题步骤、核对表和“尝试检验”来解决立体和平面图形的问题。
例子：纸巾盒、饼干盒常常是棱柱形状。
注意：要说出“为什么是棱柱”，不能只凭感觉。
solving problems = selesaikan masalah
Mr Ravi's shop sells all kinds of goods, and he wants to put the prism-shaped items together on one shelf. Which items belong there? In this lesson we use problem-solving steps, a checklist table and guess-and-check to solve problems about solids and flat shapes.
Example: tissue boxes and biscuit boxes are often prism-shaped.
Watch out: be ready to say why something is a prism, not just guess from its look.
Empat langkah
Diberi → Dicari → Cara → Semak
Gunakan langkah ini untuk setiap masalah
1. Diberi
barang dan bentuknya
2. Dicari
barang yang berbentuk prisma
3. Cara
jadual senarai semak
4. Semak
setiap prisma memenuhi semua syarat
四个步骤 = empat langkah
Diberi 是“已知”：题目给了什么资料；Dicari 是“要找”：题目问什么；Cara 是“方法”：可以画核对表，或者先猜再检查（cuba jaya）；Semak 是“检查”：答案有没有符合题目的每一个条件。
例子：已知 5 件物品，要找棱柱，方法是核对表，最后逐件检查。
注意：最后一步检查不可以省略。
four steps = empat langkah
Diberi means what is given in the problem; Dicari means what we must find; Cara is the method, such as drawing a checklist table or trying an answer and checking it (cuba jaya); Semak means checking that the answer meets every condition in the question.
Example: given 5 items and asked to find the prisms, use a checklist, then check each item.
Watch out: never skip the final checking step.
Cara: jadual senarai semak
Barang manakah prisma?
Prisma: 2 tapak sama yang bertentangan DAN semua permukaan rata
| Objek | 2 tapak sama, bertentangan | semua permukaan rata | Prisma? |
|---|---|---|---|
| kotak tisu | ✓ | ✓ | Ya |
| bola | ✗ | ✗ | Bukan |
| tin susu | ✓ | ✗ | Bukan |
| kotak coklat | ✓ | ✓ | Ya |
| khemah kecil | ✗ | ✓ | Bukan |
核对表 = jadual senarai semak
棱柱有两个条件：一，有两个形状大小一样、互相相对的底面；二，所有的面都是平的。逐件打勾：纸巾盒（长方体）和巧克力盒（三角棱柱）两项都打勾，是棱柱。牛奶罐有两个一样的圆底，但侧面是弯的，不是棱柱。球两项都不符合。小帐篷像金字塔，只有一个底面，也不是。
例子：铅笔盒是长方体，两项都符合。
注意：两个条件都要符合才是棱柱，只符合一个不算。
checklist table = jadual senarai semak
A prism must meet two conditions: one, it has two bases of the same shape and size facing each other; two, all its faces are flat. Tick each item: the tissue box (cuboid) and chocolate box (triangular prism) get both ticks, so they are prisms. The milk tin has two equal circle bases but a curved side, so it is not. The ball fails both, and the small tent, like a pyramid, has only one base.
Example: a pencil box is a cuboid and meets both conditions.
Watch out: both conditions must be met; meeting only one is not enough.
Cuba
Mengapakah tin susu tidak diletakkan di rak prisma?
牛奶罐不是棱柱 = tin susu bukan prisma
看核对表：牛奶罐有两个一样大、互相相对的圆形底面，第一个条件符合；但是它的侧面是弯的，第二个条件“所有面都是平的”不符合。所以它不是棱柱。说它没有底面或底面不一样大，都不对。
例子：一根圆柱形的蜡烛也不是棱柱。
注意：解释时要说出没有符合的是哪一个条件。
why the milk tin is not a prism = tin susu bukan prisma
In the checklist, the milk tin has two equal circle bases facing each other, so it meets the first condition, but its side is curved, so it fails the second condition that all faces are flat. That is why it is not a prism. Saying it has no base or unequal bases is wrong.
Example: a cylinder-shaped candle is not a prism either.
Watch out: when explaining, name the condition that is not met.
Cara: cuba jaya
Teka-teki poligon
“Bucu saya 2 lebih daripada pentagon.”
1. Diberi
poligon sekata; bucu 2 lebih daripada pentagon
2. Dicari
nama poligon
3. Cara
pentagon 5 bucu → 5 + 2 = 7 → heptagon
4. Semak
7 − 5 = 2 ✓
pentagon · 5
+2 →
heptagon · 7
尝试检验 = cuba jaya
谜语：“我是正多边形，我的顶点比五边形多 2 个。”先把文字变成算式：五边形有 5 个顶点，多 2 个就是 5 + 2 = 7。7 个顶点的正多边形是七边形 heptagon。再检查：7 − 5 = 2，确实多 2 个。
例子：“比正方形多 2 条边” → 4 + 2 = 6 → heksagon。
注意：“lebih”用加法，“kurang”用减法。
guess and check = cuba jaya
Riddle: “I am a regular polygon with 2 more vertices than a pentagon.” Turn the words into a number sentence: a pentagon has 5 vertices, and 2 more is 5 + 2 = 7. A regular polygon with 7 vertices is a heptagon. Check: 7 − 5 = 2, so it really has 2 more.
Example: “2 more sides than a square” gives 4 + 2 = 6, a heksagon.
Watch out: “lebih” means add and “kurang” means subtract.
Cuba
Saya poligon sekata. Sisi saya 3 kurang daripada oktagon. Siapakah saya?
比八边形少三条 = 3 kurang daripada oktagon
八边形有 8 条边。“kurang”是少，要用减法：8 − 3 = 5。5 条边的正多边形是五边形 pentagon。检查：8 − 5 = 3，确实少 3 条。选 heksagon 是只减了 2；选 heptagon 是只减了 1。
例子：比七边形少 1 条边 → 7 − 1 = 6 → heksagon。
注意：先写出八边形的边数，再计算。
three fewer than an octagon = 3 kurang daripada oktagon
An octagon has 8 sides. “Kurang” means fewer, so subtract: 8 − 3 = 5. A regular polygon with 5 sides is a pentagon. Check: 8 − 5 = 3, so it really has 3 fewer. Choosing heksagon subtracts only 2, and heptagon subtracts only 1.
Example: 1 fewer side than a heptagon gives 7 − 1 = 6, a heksagon.
Watch out: write down the octagon's number of sides before calculating.
Cara: lukis paksi simetri
Kad dengan lebih daripada satu paksi
Lukis semua paksi, kira, kemudian pilih yang lebih daripada 1
segi tiga sama sisi · 3 ✓
anak panah · 1
segi empat tepat · 2 ✓
segi empat selari · 0
超过一条对称轴 = lebih daripada satu paksi simetri
方法：在每张卡片上画出所有对称轴，再数。等边三角形 3 条，箭头 1 条，长方形 2 条，平行四边形 0 条。“lebih daripada satu”是“超过一条”，也就是 2 条或更多，所以等边三角形和长方形符合。箭头刚好 1 条，不算。
例子：正方形 4 条，也超过一条。
注意：“超过一条”不包括刚好一条。
more than one line of symmetry = lebih daripada satu paksi simetri
Method: draw every line of symmetry on each card, then count. The equilateral triangle has 3, the arrow 1, the rectangle 2 and the parallelogram 0. “Lebih daripada satu” means more than one, that is 2 or more, so the triangle and the rectangle qualify. The arrow has exactly 1, which does not count.
Example: a square has 4 lines, which is also more than one.
Watch out: “more than one” does not include exactly one.
Cuba
Kad manakah ada lebih daripada satu paksi simetri?
挑出超过一条的 = pilih yang lebih daripada satu
正六边形有 6 条对称轴，超过一条。房子只有中间竖的 1 条；风筝也只有 1 条竖的。刚好 1 条不算“超过一条”，所以答案是正六边形。
例子：圆形的标志牌有很多很多条对称轴。
注意：先数出每张卡的对称轴，再跟“超过一条”比较。
picking more than one = pilih yang lebih daripada satu
A regular hexagon has 6 lines of symmetry, which is more than one. The house has only the 1 upright line, and the kite also has just 1 upright line. Exactly one does not count as more than one, so the answer is the hexagon.
Example: a round sign has a great many lines of symmetry.
Watch out: count each card's lines first, then compare with “more than one”.
Cuba
Saya prisma. Saya ada 8 bucu dan 12 tepi. Semua permukaan saya segi empat sama. Siapakah saya?
kubus
kuboid
prisma segi tiga
用核对表猜立体 = teka bentuk dengan senarai semak
8 个顶点、12 条棱：正方体和长方体都符合；三角棱柱只有 6 个顶点、9 条棱，先排除。再看第三个线索：所有面都是正方形。长方体有长方形的面，不符合；只有正方体 6 个面都是正方形。答案是正方体。
例子：骰子就是正方体。
注意：要把每一个线索都检查过，不能只看前两个。
guessing the solid with a checklist = teka bentuk dengan senarai semak
With 8 vertices and 12 edges, both the cube and the cuboid fit, while the triangular prism has only 6 vertices and 9 edges, so it is ruled out. The third clue says every face is a square: a cuboid has rectangle faces, so only the cube, with 6 square faces, fits. The answer is the cube.
Example: a dice is a cube.
Watch out: check every clue, not just the first two.
Padankan
Masalah dan jawapannya
配对问题与答案 = padankan masalah dan jawapan
比正方形多 2 个顶点：4 + 2 = 6 → 六边形。两个圆底面加弯曲的侧面 → 圆柱体，不是棱柱。有 5 条对称轴的正多边形 → 边数也是 5 → 五边形。6 个顶点、9 条棱、两个三角形底面 → 三角棱柱。
例子：有 8 条对称轴的正多边形是八边形。
注意：每个线索先变成数字或条件，再找答案。
matching problems and answers = padankan masalah dan jawapan
2 more vertices than a square: 4 + 2 = 6, a hexagon. Two circle bases with a curved side: a cylinder, not a prism. A regular polygon with 5 lines of symmetry also has 5 sides, so it is a pentagon. 6 vertices, 9 edges and two triangle bases: a triangular prism.
Example: a regular polygon with 8 lines of symmetry is an octagon.
Watch out: turn each clue into a number or a condition first, then find the answer.
Ringkasan
Syabas!
Diberi → Dicari → Cara → Semak
Jadual senarai semak: prisma ada 2 tapak sama yang bertentangan dan semua permukaan rata. Cuba jaya: tukar klu kepada ayat matematik, contohnya 5 + 2 = 7. Lebih daripada satu paksi bermaksud 2 atau lebih.
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