Abstract
The Japanese "Kanji"--"Ijō" and "Ika" are used, individually or together, sometimes with carelessness on writing as well as on speaking. Originally, "I[以] means "with" or "together". For example, "5 Ijō [5以上]" means 5 or more, not meaning "more than 5" . Likewise, "5 Ika [5以下]" being not "less than 5" but "5 or less". Students learn notations of inequality in the second grade Math class, the Japanese "Kanji"-"I[以]" in the fourth grade Domestic Language and the combination use of "Ijō" and "Miman [未満] (meaning "less than")" in the sixth grade Math. However, while they grow up under the conditions of careless talks of people around them due to TV, radios, magazines and so on, correct knowledges they acquired in school education are apt to become fuzzy. It is very important for school education to emphasize that "Ijo" and "Ika" should not be used at the same time. In addition, it is hopeful that students should be instructed to learn the combination use of "Ijō" and "Miman (= under)" and also the one of "Cho [超] (= over)" and "Ika" , as is usually the case with legal words for practical use.
