20 in Roman numerals
20 is written XX. In chunks: X (10) + X (10) = 20.
The answer
XX
20 in Roman numerals is XX.
How XX is built
To write it, 20 is 2 tens and no ones, so it is just the tens: XX. There is no zero to write.
To read it, XX has 2 chunks, and none of them is a take-away pair, so every chunk is added.
| Chunk | Worth | Why |
|---|---|---|
| X | 10 | Add |
| X | 10 | Add |
The mistake to watch for
Miscounting the letters in XX
XX is two X's, added together. One letter more or fewer makes a different number: X is 10 and XXX is 30.
Check it with the converter
Change XX by one letter to see which number you get. The rule numbers it gives are the three rules on the Roman numerals page.
Converter set to XX (20).
Keep going
Questions parents ask
What is 20 in Roman numerals?
20 is XX.
What comes before and after XX?
19 is XIX and 21 is XXI. X stays at the front, and IX becomes X: XIX becomes XX.
Does XX use subtraction?
No. Every letter in XX is the same size as, or smaller than, the letter before it, so you just add them all.
What is the biggest letter in XX?
X, which is 10. XX has 2 letters.
Careful reading is an 11+ skill
Reading both letters of XX in order is the careful checking 11+ papers reward. The free diagnostic covers all four subjects, with no card needed.