Hyphenated tens-and-ones number
21 separates as 20 + 1. English joins “twenty” and “one” with a hyphen to form “twenty-one”.
21 in words: twenty-one
21
In words
Twenty-one
Check another number
How 21 is built
Pattern: Hyphenated tens-and-ones number
21 separates as 20 + 1. English joins “twenty” and “one” with a hyphen to form “twenty-one”.
Digit and place-value table
| Digit | Position | Value | Value in words |
|---|---|---|---|
| 2 | tens | 20 | twenty |
| 1 | ones | 1 | one |
Reading the number in groups
| Group | Digits | Reading |
|---|---|---|
| units group | 21 | twenty-one |
Why 21 is written this way
Hyphenation
The spelling contains one hyphen. Each hyphen joins a tens word to a non-zero ones word inside the same two-digit group.
Number structure
- 21 has 2 digits and 1 place-value group.
- Every digit position contributes a spoken value.
- Its single two-digit group is 21, written “twenty-one”.