Number Bases
Digit
A single symbol used to write a number; base five uses only the digits 0 to 4.
| English | Digit |
|---|---|
| Bahasa Melayu | Digit |
| 中文 | 数字 |
How it is used
In base five the only digits are 0, 1, 2, 3 and 4, so 42₅ is valid but a symbol like 5 or 7 can never appear; 42₅ = 4×5 + 2 = 22₁₀.
Where it shows up in SPM
Knowing the allowed digits is a checking tool throughout the Number Bases chapter (Form 5). Paper 1 sometimes offers an invalid number like 48₅ as a distractor; in Paper 2 spotting a digit that is too big for the base tells you a conversion or addition has gone wrong.
Don't confuse it with
Open the chapter: Number Bases →
Frequently asked questions
Can a number in base five contain the digit 5?
No. Base five only has the digits 0 to 4, and the quantity five is written as 10₅.
If you ever see a 5, 6, 7, 8 or 9 in a base-five number, it is not a valid base-five number.
What is the biggest digit in base eight?
It is 7, because the largest digit is always one less than the base. So base eight uses 0 to 7, and the next number after 7₈ is 10₈, which equals eight in base ten.