China translated western scientific works in modern times into "rational numbers" according to Japanese translation methods. However, this word comes from ancient Greece, and its English root is ratio, which means ratio (the root here is English and the Greek meaning is the same).
So the meaning of this word is also very clear, that is, the "ratio" of integers. In contrast, "irrational number" is a number that cannot be accurately expressed as the ratio of two integers, but it is not unreasonable.
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Proposer of rational numbers: Pythagoras (about 580 ~ 500 BC), an ancient Greek mathematician and philosopher. Pythagoras was born in a noble family on Samos Island (an island in eastern Greece today) in the Aegean Sea. He was smart and studious since childhood, and studied geometry, natural science and philosophy with famous teachers.
Later, because of longing for the wisdom of the East, he traveled to Babylon and India, two ancient civilizations with high cultural level in the world, and absorbed the culture of Arab civilization and Indian civilization (480 BC).
Later, he went to southern Italy to teach mathematics and publicize his philosophical thoughts. Later, he and his followers formed Pythagoras' political and religious groups.
Baidu encyclopedia-rational number