30 in Roman numerals
30 is written XXX. In chunks: X (10) + X (10) + X (10) = 30.
The answer
XXX
30 in Roman numerals is XXX.
How XXX is built
To write it, 30 is 3 tens and no ones, so it is just the tens: XXX. There is no zero to write.
To read it, XXX has 3 chunks, and none of them is a take-away pair, so every chunk is added.
| Chunk | Worth | Why |
|---|---|---|
| X | 10 | Add |
| X | 10 | Add |
| X | 10 | Add |
The mistake to watch for
Miscounting the letters in XXX
XXX is three X's, all added together. One letter more or fewer makes a different number: XX is 20.
Check it with the converter
Change the number 30 by one to see how its numeral changes. The rule numbers it gives are the three rules on the Roman numerals page.
Converter set to XXX (30).
Keep going
Questions parents ask
What is 30 in Roman numerals?
30 is XXX.
What comes before and after XXX?
29 is XXIX and 31 is XXXI. XX stays at the front, and IX becomes X: XXIX becomes XXX.
Does XXX use subtraction?
No. Every letter in XXX is the same size as, or smaller than, the letter before it, so you just add them all.
What is the biggest letter in XXX?
X, which is 10. XXX has 3 letters.
Where might you see XXX?
London 2012 was officially the Games of the XXX Olympiad.
Want to practise more?
Explore the diagnostic for more practice activities.