Pronunciation of the word “one” is as important as it is vital. Therefore, a great degree of teaching is required.
As most students revert to lesser pronunciations such as “wun”, “wuhn”, or “won”, it is the duty of the teacher to repeatedly yell “one” while pointing to the written word.
In addition to pronunciation of the word being of higher difficulty for the Japanese students, up until the late 1800s there was no concept of “1” or “0” in Japanese, lending to their concept of teamwork. If they used Katakana to write “team”, it would look like “chiimu” (チーム), but still wouldn’t have an “i” in it because it would have two “i”s.
If the student is unfamiliar with the concept of 1 and 0, it is best to draw an image of a group of people. Ask the student to provide names and short backgrounds for each image of a person. After that has been established, explain that they are all dying, and use a red marker to represent blood, and a black marker to cross out their eyes or draw widows. With one person left alive, say the word “one” and have the student repeat. Draw a representation of death for the final person and say “zero” and have the student repeat. This will help the student to associate the numbers with the concept.