Numbers With Integrity
Some things in math (especially names for things) make sense, some don't!
Counting numbers... Makes sense. Whole numbers... makes sense. Fractions and rational numbers...make sense.
But, negative numbers...puzzlement. In fact, historically, Europeans in the 16th century claimed that the notion of 4-6 was absurd!
In 1545, Italian mathematician Cardano discussed these numbers, calling the positive numbers "true" numbers and the negative numbers "fictitious" numbers.
Later, the word integer was used to describe the full set of positive and negative numbers... it means "numbers with integrity."
I will let you explore the troubles with the notion of "complex" and "imaginary" numbers...that is a fascinating story all by itself.