Operations on Sets
Element
A member of a set, written with the symbol ∈.
| English | Element |
|---|---|
| Bahasa Melayu | Unsur |
| 中文 | 元素 |
How it is used
For the set A = {2, 3, 5, 7}, we write 3 ∈ A (3 is an element of A) but 4 ∉ A (4 is not an element of A). The set A has 4 elements, so n(A) = 4.
Where it shows up in SPM
In the Sets and Operations on Sets chapters (Form 4). Paper 1 tests the symbols ∈ and ∉ and asks for n(A), the number of elements; understanding elements underlies every later set operation.
Don't confuse it with
Open the chapter: Operations on Sets →
Frequently asked questions
What is the difference between 3 and {3}?
3 is an element, a single number; {3} is a set containing that one element. So 3 ∈ {3} is correct, and {3} ⊂ {1, 3, 5} is correct, but 3 ⊂ {1, 3, 5} is wrong because 3 is not a set.
Can a set have no elements?
Yes. A set with no elements is the empty set, written { } or ∅, and n(∅) = 0.
For example, the set of whole numbers between 3 and 4 is empty because none exist.