A more neutral suffix for counting would be –tsu. If you are not sure which to use, this one will be more widely understood by the Japanese listener. Adding this suffix to numbers is a little tricky because the first several numbers will take irregular form.
| 1 | 一つ | ひとつ | |
| 2 | 二つ | ふたつ | |
| 3 | 三つ | みっつ | |
| 4 | 四つ | よっつ | |
| 5 | 五つ | いつつ | |
| 6 | 六つ | むっつ | |
| 7 | 七つ | ななつ | |
| 8 | 八つ | やっつ | |
| 9 | 九つ | ここのつ | |
| 10 | 十 | とお | |
| 11 | 十一/十一個 | じゅういち/じゅういっこ | |
| 12 | 十二/十二個 | じゅうに/じゅうにこ | |
| 100 | 百/百個 | ひゃく/ひゃっこ | |
| 1,000 | 千/千個 | せん/せんこ | |
| 10,000 | 一万/一万個 | いちまん/いちまんこ | |
| How many | いくつ | いくつ |
Iggy Japanese 